21037967 has 2 divisors, whose sum is σ = 21037968. Its totient is φ = 21037966.

The previous prime is 21037957. The next prime is 21038009. The reversal of 21037967 is 76973012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21037967 - 2²⁰ = 19989391 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21037957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518983 + 10518984.

It is an arithmetic number, because the mean of its divisors is an integer number (10518984).

Almost surely, 2^21037967 is an apocalyptic number.

21037967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21037967 is an equidigital number, since it uses as much as digits as its factorization.

21037967 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 21037967 is about 4586.7163635874. The cubic root of 21037967 is about 276.0585843223.

The spelling of 21037967 in words is "twenty-one million, thirty-seven thousand, nine hundred sixty-seven".