21721514814 has 24 divisors (see below), whose sum is σ = 47080773480. Its totient is φ = 7237813968.

The previous prime is 21721514767. The next prime is 21721514821. The reversal of 21721514814 is 41841512712.

21721514814 is a `hidden beast` number, since 2 + 172 + 1 + 5 + 1 + 481 + 4 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 174169 + ... + 271620.

It is an arithmetic number, because the mean of its divisors is an integer number (1961698895).

Almost surely, 2^21721514814 is an apocalyptic number.

21721514814 is an abundant number, since it is smaller than the sum of its proper divisors (25359258666).

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

21721514814 is a wasteful number, since it uses less digits than its factorization.

21721514814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448504 (or 448501 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The spelling of 21721514814 in words is "twenty-one billion, seven hundred twenty-one million, five hundred fourteen thousand, eight hundred fourteen".