35721 has 21 divisors (see below), whose sum is σ = 62301. Its totient is φ = 20412.

The previous prime is 35677. The next prime is 35729. The reversal of 35721 is 12753.

Subtracting from 35721 its product of digits (210), we obtain a triangular number (35511 = T_{266}).

It can be divided in two parts, 357 and 21, that added together give a triangular number (378 = T_{27}).

35721 = T_{188} + T_{189}.

The square root of 35721 is 189.

It is a perfect power (a square), and thus also a powerful number.

It is a tau number, because it is divible by the number of its divisors (21).

It is not a de Polignac number, because 35721 - 2^{7} = 35593 is a prime.

Its product of digits (210) is a multiple of the sum of its prime divisors (10).

It is a Curzon number.

35721 is a lucky number.

It is a plaindrome in base 13.

It is a nialpdrome in base 9.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 35694 and 35703.

It is not an unprimeable number, because it can be changed into a prime (35729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 5100 + ... + 5106.

35721 is a Friedman number, since it can be written as 21*7*3^5, using all its digits and the basic arithmetic operations.

2^{35721} is an apocalyptic number.

35721 is the 189-th square number.

35721 is the 95-th centered octagonal number.

It is an amenable number.

35721 is a deficient number, since it is larger than the sum of its proper divisors (26580).

35721 is an frugal number, since it uses more digits than its factorization.

35721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32 (or 10 counting only the distinct ones).

The product of its digits is 210, while the sum is 18.

The cubic root of 35721 is about 32.9337513902.

The spelling of 35721 in words is "thirty-five thousand, seven hundred twenty-one".

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