21136137 has 16 divisors (see below), whose sum is σ = 30870720. Its totient is φ = 12756800.

The previous prime is 21136133. The next prime is 21136147. The reversal of 21136137 is 73163112.

It is a cyclic number.

It is not a de Polignac number, because 21136137 - 2² = 21136133 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21136133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7687 + ... + 10067.

It is an arithmetic number, because the mean of its divisors is an integer number (1929420).

Almost surely, 2^21136137 is an apocalyptic number.

It is an amenable number.

21136137 is a deficient number, since it is larger than the sum of its proper divisors (9734583).

21136137 is a wasteful number, since it uses less digits than its factorization.

21136137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664.

The product of its digits is 756, while the sum is 24.

The square root of 21136137 is about 4597.4054639546. The cubic root of 21136137 is about 276.4873112147.

Adding to 21136137 its reverse (73163112), we get a palindrome (94299249).

The spelling of 21136137 in words is "twenty-one million, one hundred thirty-six thousand, one hundred thirty-seven".