21621265773020 has 48 divisors (see below), whose sum is σ = 45480128254848. Its totient is φ = 8634134515200.

The previous prime is 21621265773013. The next prime is 21621265773067. The reversal of 21621265773020 is 2037756212612.

It is a super-2 number, since 2×21621265773020² (a number of 27 digits) contains 22 as substring.

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, 103735952 + ... + 103944168.

It is an arithmetic number, because the mean of its divisors is an integer number (947502671976).

Almost surely, 2^{21621265773020} is an apocalyptic number.

21621265773020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21621265773020 is an abundant number, since it is smaller than the sum of its proper divisors (23858862481828).

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

21621265773020 is a wasteful number, since it uses less digits than its factorization.

21621265773020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216830 (or 216828 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 44.

The spelling of 21621265773020 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred sixty-five million, seven hundred seventy-three thousand, twenty".