21905037 has 48 divisors (see below), whose sum is σ = 40080768. Its totient is φ = 11197440.

The previous prime is 21905011. The next prime is 21905053. The reversal of 21905037 is 73050912.

It is not a de Polignac number, because 21905037 - 2⁸ = 21904781 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21905037.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21905077) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50373 + ... + 50805.

It is an arithmetic number, because the mean of its divisors is an integer number (835016).

Almost surely, 2^21905037 is an apocalyptic number.

It is an amenable number.

21905037 is a deficient number, since it is larger than the sum of its proper divisors (18175731).

21905037 is a wasteful number, since it uses less digits than its factorization.

21905037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 21905037 is about 4680.2817222898. The cubic root of 21905037 is about 279.8001848216.

Adding to 21905037 its reverse (73050912), we get a palindrome (94955949).

It can be divided in two parts, 2190 and 5037, that added together give a palindrome (7227).

The spelling of 21905037 in words is "twenty-one million, nine hundred five thousand, thirty-seven".