21355472261660 has 24 divisors (see below), whose sum is σ = 45478132481376. Its totient is φ = 8421876384320.

The previous prime is 21355472261573. The next prime is 21355472261777. The reversal of 21355472261660 is 6616227455312.

It is a junction number, because it is equal to n+sod(n) for n = 21355472261599 and 21355472261608.

It is a congruent number.

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, 7519531067 + ... + 7519533906.

It is an arithmetic number, because the mean of its divisors is an integer number (1894922186724).

Almost surely, 2^{21355472261660} is an apocalyptic number.

21355472261660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21355472261660 is an abundant number, since it is smaller than the sum of its proper divisors (24122660219716).

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

21355472261660 is a wasteful number, since it uses less digits than its factorization.

21355472261660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15039065053 (or 15039065051 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 50.

The spelling of 21355472261660 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred seventy-two million, two hundred sixty-one thousand, six hundred sixty".