21142977764820 has 96 divisors (see below), whose sum is σ = 59391417456000. Its totient is φ = 5619941021184.

The previous prime is 21142977764807. The next prime is 21142977764899. The reversal of 21142977764820 is 2846777924112.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58220647 + ... + 58582673.

It is an arithmetic number, because the mean of its divisors is an integer number (618660598500).

Almost surely, 2^{21142977764820} is an apocalyptic number.

21142977764820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21142977764820 is an abundant number, since it is smaller than the sum of its proper divisors (38248439691180).

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

21142977764820 is a wasteful number, since it uses less digits than its factorization.

21142977764820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365177 (or 365175 counting only the distinct ones).

The product of its (nonzero) digits is 18966528, while the sum is 60.

The spelling of 21142977764820 in words is "twenty-one trillion, one hundred forty-two billion, nine hundred seventy-seven million, seven hundred sixty-four thousand, eight hundred twenty".