20931386 has 32 divisors (see below), whose sum is σ = 39232512. Its totient is φ = 8167680.

The previous prime is 20931377. The next prime is 20931389. The reversal of 20931386 is 68313902.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20931389) 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, 5960 + ... + 8796.

It is an arithmetic number, because the mean of its divisors is an integer number (1226016).

Almost surely, 2^20931386 is an apocalyptic number.

20931386 is a deficient number, since it is larger than the sum of its proper divisors (18301126).

20931386 is a wasteful number, since it uses less digits than its factorization.

20931386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2894.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20931386 is about 4575.0831686429. The cubic root of 20931386 is about 275.5916122919.

The spelling of 20931386 in words is "twenty million, nine hundred thirty-one thousand, three hundred eighty-six".