21609727929072 has 240 divisors, whose sum is σ = 67637571775488. Its totient is φ = 6408249845760.

The previous prime is 21609727929061. The next prime is 21609727929109. The reversal of 21609727929072 is 27092972790612.

21609727929072 is a `hidden beast` number, since 2 + 1 + 6 + 0 + 9 + 7 + 279 + 290 + 72 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 47958 + ... + 6574325.

Almost surely, 2^{21609727929072} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21609727929072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33818785887744).

21609727929072 is an abundant number, since it is smaller than the sum of its proper divisors (46027843846416).

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

21609727929072 is a wasteful number, since it uses less digits than its factorization.

21609727929072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6622388 (or 6622379 counting only the distinct ones).

The product of its (nonzero) digits is 24004512, while the sum is 63.

The spelling of 21609727929072 in words is "twenty-one trillion, six hundred nine billion, seven hundred twenty-seven million, nine hundred twenty-nine thousand, seventy-two".