21037641 has 4 divisors (see below), whose sum is σ = 28050192. Its totient is φ = 14025092.

The previous prime is 21037631. The next prime is 21037649. The reversal of 21037641 is 14673012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21037641 - 2⁵ = 21037609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21037649) 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 3 ways as a sum of consecutive naturals, for example, 3506271 + ... + 3506276.

It is an arithmetic number, because the mean of its divisors is an integer number (7012548).

Almost surely, 2^21037641 is an apocalyptic number.

It is an amenable number.

21037641 is a deficient number, since it is larger than the sum of its proper divisors (7012551).

21037641 is an equidigital number, since it uses as much as digits as its factorization.

21037641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7012550.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21037641 is about 4586.6808260440. The cubic root of 21037641 is about 276.0571583993.

The spelling of 21037641 in words is "twenty-one million, thirty-seven thousand, six hundred forty-one".