1621563622660 has 24 divisors (see below), whose sum is σ = 3488339307096. Its totient is φ = 632805315840.

The previous prime is 1621563622607. The next prime is 1621563622687. The reversal of 1621563622660 is 662263651261.

It can be written as a sum of positive squares in 4 ways, for example, as 204378134724 + 1417185487936 = 452082^2 + 1190456^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1621563622660.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 988757487 + ... + 988759126.

It is an arithmetic number, because the mean of its divisors is an integer number (145347471129).

Almost surely, 2^{1621563622660} is an apocalyptic number.

1621563622660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621563622660 is an abundant number, since it is smaller than the sum of its proper divisors (1866775684436).

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

1621563622660 is a wasteful number, since it uses less digits than its factorization.

1621563622660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1977516663 (or 1977516661 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 1621563622660 in words is "one trillion, six hundred twenty-one billion, five hundred sixty-three million, six hundred twenty-two thousand, six hundred sixty".