20646432 has 72 divisors (see below), whose sum is σ = 62181756. Its totient is φ = 6475776.

The previous prime is 20646421. The next prime is 20646443. The reversal of 20646432 is 23464602.

It is an interprime number because it is at equal distance from previous prime (20646421) and next prime (20646443).

It can be written as a sum of positive squares in 2 ways, for example, as 17943696 + 2702736 = 4236^2 + 1644^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20646396 and 20646405.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2788 + ... + 7004.

Almost surely, 2^20646432 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 20646432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31090878).

20646432 is an abundant number, since it is smaller than the sum of its proper divisors (41535324).

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

20646432 is a wasteful number, since it uses less digits than its factorization.

20646432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4250 (or 4239 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 20646432 is about 4543.8345040285. The cubic root of 20646432 is about 274.3352849395.

The spelling of 20646432 in words is "twenty million, six hundred forty-six thousand, four hundred thirty-two".