20256642 has 40 divisors (see below), whose sum is σ = 51877056. Its totient is φ = 5787288.

The previous prime is 20256637. The next prime is 20256659. The reversal of 20256642 is 24665202.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 19 ways as a sum of consecutive naturals, for example, 7798 + ... + 10065.

Almost surely, 2^20256642 is an apocalyptic number.

20256642 is an abundant number, since it is smaller than the sum of its proper divisors (31620414).

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

20256642 is a wasteful number, since it uses less digits than its factorization.

20256642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17884 (or 17875 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 20256642 is about 4500.7379394939. The cubic root of 20256642 is about 272.5978864449.

The spelling of 20256642 in words is "twenty million, two hundred fifty-six thousand, six hundred forty-two".