21495937 has 4 divisors (see below), whose sum is σ = 21522880. Its totient is φ = 21468996.

The previous prime is 21495917. The next prime is 21495941. The reversal of 21495937 is 73959412.

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 21495937 - 2⁷ = 21495809 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 21495937.

It is not an unprimeable number, because it can be changed into a prime (21495917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12237 + ... + 13882.

It is an arithmetic number, because the mean of its divisors is an integer number (5380720).

Almost surely, 2^21495937 is an apocalyptic number.

It is an amenable number.

21495937 is a deficient number, since it is larger than the sum of its proper divisors (26943).

21495937 is an equidigital number, since it uses as much as digits as its factorization.

21495937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26942.

The product of its digits is 68040, while the sum is 40.

The square root of 21495937 is about 4636.3711024895. The cubic root of 21495937 is about 278.0473712902.

The spelling of 21495937 in words is "twenty-one million, four hundred ninety-five thousand, nine hundred thirty-seven".