20646456 has 64 divisors (see below), whose sum is σ = 54501120. Its totient is φ = 6504960.

The previous prime is 20646443. The next prime is 20646467. The reversal of 20646456 is 65464602.

It is a super-2 number, since 2×20646456² = 852552290719872, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62211 + ... + 62541.

It is an arithmetic number, because the mean of its divisors is an integer number (851580).

Almost surely, 2^20646456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20646456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27250560).

20646456 is an abundant number, since it is smaller than the sum of its proper divisors (33854664).

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

20646456 is a wasteful number, since it uses less digits than its factorization.

20646456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 20646456 is about 4543.8371449690. The cubic root of 20646456 is about 274.3353912379.

The spelling of 20646456 in words is "twenty million, six hundred forty-six thousand, four hundred fifty-six".