20642886 has 48 divisors (see below), whose sum is σ = 49213008. Its totient is φ = 6201600.

The previous prime is 20642857. The next prime is 20642899. The reversal of 20642886 is 68824602.

20642886 is a `hidden beast` number, since 2 + 0 + 642 + 8 + 8 + 6 = 666.

It is a super-2 number, since 2×20642886² = 852257484817992, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20642886.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26746 + ... + 27506.

It is an arithmetic number, because the mean of its divisors is an integer number (1025271).

Almost surely, 2^20642886 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20642886, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24606504).

20642886 is an abundant number, since it is smaller than the sum of its proper divisors (28570122).

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

20642886 is a wasteful number, since it uses less digits than its factorization.

20642886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 917 (or 914 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 20642886 is about 4543.4442882025. Note that the first 3 decimals coincide. The cubic root of 20642886 is about 274.3195784546.

It can be divided in two parts, 20642 and 886, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 20642886 in words is "twenty million, six hundred forty-two thousand, eight hundred eighty-six".