21642950028 has 48 divisors (see below), whose sum is σ = 57722196224. Its totient is φ = 6182879040.

The previous prime is 21642950023. The next prime is 21642950033. The reversal of 21642950028 is 82005924612.

It is an interprime number because it is at equal distance from previous prime (21642950023) and next prime (21642950033).

It is not an unprimeable number, because it can be changed into a prime (21642950023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 929043 + ... + 952053.

Almost surely, 2^21642950028 is an apocalyptic number.

21642950028 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21642950028 is an abundant number, since it is smaller than the sum of its proper divisors (36079246196).

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

21642950028 is a wasteful number, since it uses less digits than its factorization.

21642950028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34222 (or 34220 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The spelling of 21642950028 in words is "twenty-one billion, six hundred forty-two million, nine hundred fifty thousand, twenty-eight".