20643672 has 64 divisors (see below), whose sum is σ = 59604480. Its totient is φ = 5836032.

The previous prime is 20643643. The next prime is 20643683. The reversal of 20643672 is 27634602.

It is a super-2 number, since 2×20643672² = 852322387287168, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16708 + ... + 17900.

It is an arithmetic number, because the mean of its divisors is an integer number (931320).

Almost surely, 2^20643672 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 20643672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29802240).

20643672 is an abundant number, since it is smaller than the sum of its proper divisors (38960808).

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

20643672 is a wasteful number, since it uses less digits than its factorization.

20643672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1312 (or 1308 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 30.

The square root of 20643672 is about 4543.5307856336. The cubic root of 20643672 is about 274.3230600811.

The spelling of 20643672 in words is "twenty million, six hundred forty-three thousand, six hundred seventy-two".