21971587512996 has 729 divisors, whose sum is σ = 66167728697889. Its totient is φ = 6142350614400.

The previous prime is 21971587512949. The next prime is 21971587513009. The reversal of 21971587512996 is 69921578517912.

The square root of 21971587512996 is 4687386.

It is a perfect power (a square), and thus also a powerful number.

21971587512996 is a `hidden beast` number, since 2 + 1 + 9 + 7 + 15 + 8 + 7 + 512 + 9 + 96 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11521367530596 + 10450219982400 = 3394314^2 + 3232680^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 278121360885 + ... + 278121360963.

Almost surely, 2^{21971587512996} is an apocalyptic number.

21971587512996 is the 4687386-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21971587512996

21971587512996 is an abundant number, since it is smaller than the sum of its proper divisors (44196141184893).

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

21971587512996 is a wasteful number, since it uses less digits than its factorization.

21971587512996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 155 counting only the distinct ones).

The product of its digits is 171460800, while the sum is 72.

The spelling of 21971587512996 in words is "twenty-one trillion, nine hundred seventy-one billion, five hundred eighty-seven million, five hundred twelve thousand, nine hundred ninety-six".