21985406960 has 80 divisors (see below), whose sum is σ = 56338081632. Its totient is φ = 7912243200.

The previous prime is 21985406903. The next prime is 21985407019. The reversal of 21985406960 is 6960458912.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 21985406899 and 21985406908.

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, 43421 + ... + 214140.

Almost surely, 2^21985406960 is an apocalyptic number.

21985406960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21985406960 is an abundant number, since it is smaller than the sum of its proper divisors (34352674672).

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

21985406960 is a wasteful number, since it uses less digits than its factorization.

21985406960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257682 (or 257676 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 50.

The spelling of 21985406960 in words is "twenty-one billion, nine hundred eighty-five million, four hundred six thousand, nine hundred sixty".