20406972 has 24 divisors (see below), whose sum is σ = 47967696. Its totient is φ = 6752128.

The previous prime is 20406941. The next prime is 20406973. The reversal of 20406972 is 27960402.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20406973) 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, 4563 + ... + 7850.

It is an arithmetic number, because the mean of its divisors is an integer number (1998654).

Almost surely, 2^20406972 is an apocalyptic number.

It is an amenable number.

20406972 is an abundant number, since it is smaller than the sum of its proper divisors (27560724).

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

20406972 is a wasteful number, since it uses less digits than its factorization.

20406972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12557 (or 12555 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 20406972 is about 4517.4076636939. The cubic root of 20406972 is about 273.2705659298.

The spelling of 20406972 in words is "twenty million, four hundred six thousand, nine hundred seventy-two".