20878137 has 12 divisors (see below), whose sum is σ = 34465600. Its totient is φ = 11930328.

The previous prime is 20878133. The next prime is 20878163. The reversal of 20878137 is 73187802.

It is not a de Polignac number, because 20878137 - 2² = 20878133 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20878133) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165637 + ... + 165762.

Almost surely, 2^20878137 is an apocalyptic number.

It is an amenable number.

20878137 is a deficient number, since it is larger than the sum of its proper divisors (13587463).

20878137 is a wasteful number, since it uses less digits than its factorization.

20878137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331412 (or 331409 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 20878137 is about 4569.2600057340. The cubic root of 20878137 is about 275.3577141057.

The spelling of 20878137 in words is "twenty million, eight hundred seventy-eight thousand, one hundred thirty-seven".