21413781680 has 40 divisors (see below), whose sum is σ = 50006410992. Its totient is φ = 8527771904.

The previous prime is 21413781677. The next prime is 21413781737. The reversal of 21413781680 is 8618731412.

It is a tau number, because it is divible by the number of its divisors (40).

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, 571427 + ... + 607746.

Almost surely, 2^21413781680 is an apocalyptic number.

21413781680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21413781680 is an abundant number, since it is smaller than the sum of its proper divisors (28592629312).

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

21413781680 is a wasteful number, since it uses less digits than its factorization.

21413781680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1179413 (or 1179407 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 41.

The spelling of 21413781680 in words is "twenty-one billion, four hundred thirteen million, seven hundred eighty-one thousand, six hundred eighty".