20215137 has 8 divisors (see below), whose sum is σ = 28125504. Its totient is φ = 12890768.

The previous prime is 20215133. The next prime is 20215147. The reversal of 20215137 is 73151202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20215137 - 2² = 20215133 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20215133) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146418 + ... + 146555.

It is an arithmetic number, because the mean of its divisors is an integer number (3515688).

Almost surely, 2^20215137 is an apocalyptic number.

It is an amenable number.

20215137 is a deficient number, since it is larger than the sum of its proper divisors (7910367).

20215137 is a wasteful number, since it uses less digits than its factorization.

20215137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292999.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 20215137 is about 4496.1246646418. The cubic root of 20215137 is about 272.4115786402.

Adding to 20215137 its reverse (73151202), we get a palindrome (93366339).

The spelling of 20215137 in words is "twenty million, two hundred fifteen thousand, one hundred thirty-seven".