20931418 has 16 divisors (see below), whose sum is σ = 32781384. Its totient is φ = 10013760.

The previous prime is 20931413. The next prime is 20931419. The reversal of 20931418 is 81413902.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14311089 + 6620329 = 3783^2 + 2573^2 .

It is not an unprimeable number, because it can be changed into a prime (20931413) 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, 2196 + ... + 6832.

Almost surely, 2^20931418 is an apocalyptic number.

20931418 is a deficient number, since it is larger than the sum of its proper divisors (11849966).

20931418 is a wasteful number, since it uses less digits than its factorization.

20931418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4737.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 20931418 is about 4575.0866658458. The cubic root of 20931418 is about 275.5917527337.

The spelling of 20931418 in words is "twenty million, nine hundred thirty-one thousand, four hundred eighteen".