20451956 has 24 divisors (see below), whose sum is σ = 41776896. Its totient is φ = 8578080.

The previous prime is 20451941. The next prime is 20451967. The reversal of 20451956 is 65915402.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6455 + ... + 9086.

It is an arithmetic number, because the mean of its divisors is an integer number (1740704).

Almost surely, 2^20451956 is an apocalyptic number.

It is an amenable number.

20451956 is an abundant number, since it is smaller than the sum of its proper divisors (21324940).

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

20451956 is a wasteful number, since it uses less digits than its factorization.

20451956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15599 (or 15597 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 20451956 is about 4522.3838846343. The cubic root of 20451956 is about 273.4712127424.

The spelling of 20451956 in words is "twenty million, four hundred fifty-one thousand, nine hundred fifty-six".