1835721 has 6 divisors (see below), whose sum is σ = 2651610. Its totient is φ = 1223808.

The previous prime is 1835689. The next prime is 1835737. The reversal of 1835721 is 1275381.

It can be written as a sum of positive squares in only one way, i.e., 1527696 + 308025 = 1236^2 + 555^2 .

It is not a de Polignac number, because 1835721 - 2⁵ = 1835689 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1835741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101976 + ... + 101993.

It is an arithmetic number, because the mean of its divisors is an integer number (441935).

2^1835721 is an apocalyptic number.

It is an amenable number.

1835721 is a deficient number, since it is larger than the sum of its proper divisors (815889).

1835721 is a wasteful number, since it uses less digits than its factorization.

1835721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203975 (or 203972 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 1835721 is about 1354.8878182344. The cubic root of 1835721 is about 122.4434502282.

It can be divided in two parts, 1835 and 721, that added together give a triangular number (2556 = T₇₁).

The spelling of 1835721 in words is "one million, eight hundred thirty-five thousand, seven hundred twenty-one".