21337901 has 4 divisors (see below), whose sum is σ = 22979292. Its totient is φ = 19696512.

The previous prime is 21337891. The next prime is 21337913. The reversal of 21337901 is 10973312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11383876 + 9954025 = 3374^2 + 3155^2 .

It is a cyclic number.

It is not a de Polignac number, because 21337901 - 2⁶ = 21337837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21337801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 820676 + ... + 820701.

It is an arithmetic number, because the mean of its divisors is an integer number (5744823).

Almost surely, 2^21337901 is an apocalyptic number.

It is an amenable number.

21337901 is a deficient number, since it is larger than the sum of its proper divisors (1641391).

21337901 is a wasteful number, since it uses less digits than its factorization.

21337901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1641390.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 21337901 is about 4619.2965914736. The cubic root of 21337901 is about 277.3643023476.

The spelling of 21337901 in words is "twenty-one million, three hundred thirty-seven thousand, nine hundred one".