20931678 has 24 divisors (see below), whose sum is σ = 46917000. Its totient is φ = 6736464.

The previous prime is 20931667. The next prime is 20931683. The reversal of 20931678 is 87613902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19528 + ... + 20571.

It is an arithmetic number, because the mean of its divisors is an integer number (1954875).

Almost surely, 2^20931678 is an apocalyptic number.

20931678 is an abundant number, since it is smaller than the sum of its proper divisors (25985322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20931678 is a wasteful number, since it uses less digits than its factorization.

20931678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40136 (or 40133 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 20931678 is about 4575.1150805198. The cubic root of 20931678 is about 275.5928938184.

It can be divided in two parts, 20931 and 678, that added together give a square (21609 = 147²).

The spelling of 20931678 in words is "twenty million, nine hundred thirty-one thousand, six hundred seventy-eight".