21367937 has 4 divisors (see below), whose sum is σ = 21397440. Its totient is φ = 21338436.

The previous prime is 21367933. The next prime is 21367979. The reversal of 21367937 is 73976312.

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 21367937 - 2² = 21367933 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21367937.

It is not an unprimeable number, because it can be changed into a prime (21367933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13637 + ... + 15122.

It is an arithmetic number, because the mean of its divisors is an integer number (5349360).

Almost surely, 2^21367937 is an apocalyptic number.

It is an amenable number.

21367937 is a deficient number, since it is larger than the sum of its proper divisors (29503).

21367937 is an equidigital number, since it uses as much as digits as its factorization.

21367937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29502.

The product of its digits is 47628, while the sum is 38.

The square root of 21367937 is about 4622.5465925180. The cubic root of 21367937 is about 277.4943840002.

The spelling of 21367937 in words is "twenty-one million, three hundred sixty-seven thousand, nine hundred thirty-seven".