20831406 has 8 divisors (see below), whose sum is σ = 41662824. Its totient is φ = 6943800.

The previous prime is 20831323. The next prime is 20831533. The reversal of 20831406 is 60413802.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

20831406 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1735945 + ... + 1735956.

It is an arithmetic number, because the mean of its divisors is an integer number (5207853).

Almost surely, 2^20831406 is an apocalyptic number.

20831406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20831406 is a wasteful number, since it uses less digits than its factorization.

20831406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3471906.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 20831406 is about 4564.1435122047. The cubic root of 20831406 is about 275.1521185936.

The spelling of 20831406 in words is "twenty million, eight hundred thirty-one thousand, four hundred six".