21905116240 has 80 divisors (see below), whose sum is σ = 59303311488. Its totient is φ = 7368611328.

The previous prime is 21905116223. The next prime is 21905116279. The reversal of 21905116240 is 4261150912.

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

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, 339342 + ... + 398701.

Almost surely, 2^21905116240 is an apocalyptic number.

21905116240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21905116240 is an abundant number, since it is smaller than the sum of its proper divisors (37398195248).

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

21905116240 is a wasteful number, since it uses less digits than its factorization.

21905116240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738116 (or 738110 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 21905116240 in words is "twenty-one billion, nine hundred five million, one hundred sixteen thousand, two hundred forty".