21250642176 has 81 divisors (see below), whose sum is σ = 61291021701. Its totient is φ = 7081214976.

The previous prime is 21250642159. The next prime is 21250642267. The reversal of 21250642176 is 67124605212.

It is a happy number.

The square root of 21250642176 is 145776.

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

21250642176 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 0 + 642 + 1 + 7 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17998905600 + 3251736576 = 134160^2 + 57024^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21250642176.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6995730 + ... + 6998766.

Almost surely, 2^21250642176 is an apocalyptic number.

21250642176 is the 145776-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21250642176

21250642176 is an abundant number, since it is smaller than the sum of its proper divisors (40040379525).

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

21250642176 is an frugal number, since it uses more digits than its factorization.

21250642176 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6096 (or 3042 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

Multiplying 21250642176 by its sum of digits (36), we get a square (765023118336 = 874656²).

21250642176 divided by its sum of digits (36) gives a square (590295616 = 24296²).

The spelling of 21250642176 in words is "twenty-one billion, two hundred fifty million, six hundred forty-two thousand, one hundred seventy-six".