1621260556100 has 18 divisors (see below), whose sum is σ = 3518135406954. Its totient is φ = 648504222400.

The previous prime is 1621260556087. The next prime is 1621260556129. The reversal of 1621260556100 is 16550621261.

It can be written as a sum of positive squares in 3 ways, for example, as 115235807296 + 1506024748804 = 339464^2 + 1227202^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8106302681 + ... + 8106302880.

It is an arithmetic number, because the mean of its divisors is an integer number (195451967053).

Almost surely, 2^{1621260556100} is an apocalyptic number.

1621260556100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621260556100 is an abundant number, since it is smaller than the sum of its proper divisors (1896874850854).

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

1621260556100 is a wasteful number, since it uses less digits than its factorization.

1621260556100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16212605575 (or 16212605568 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 35.

It can be divided in two parts, 16 and 21260556100, that multiplied together give a square (340168897600 = 583240²).

The spelling of 1621260556100 in words is "one trillion, six hundred twenty-one billion, two hundred sixty million, five hundred fifty-six thousand, one hundred".