20406872 has 8 divisors (see below), whose sum is σ = 38262900. Its totient is φ = 10203432.

The previous prime is 20406833. The next prime is 20406917. The reversal of 20406872 is 27860402.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1275422 + ... + 1275437.

Almost surely, 2^20406872 is an apocalyptic number.

It is an amenable number.

20406872 is a deficient number, since it is larger than the sum of its proper divisors (17856028).

20406872 is a wasteful number, since it uses less digits than its factorization.

20406872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2550865 (or 2550861 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 20406872 is about 4517.3965953854. The cubic root of 20406872 is about 273.2701195611.

The spelling of 20406872 in words is "twenty million, four hundred six thousand, eight hundred seventy-two".