21749170576 has 135 divisors (see below), whose sum is σ = 51467520321. Its totient is φ = 8876875392.

The previous prime is 21749170501. The next prime is 21749170601. The reversal of 21749170576 is 67507194712.

The square root of 21749170576 is 147476.

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

It can be written as a sum of positive squares in only one way, i.e., 20256120976 + 1493049600 = 142324^2 + 38640^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 94974430 + ... + 94974658.

Almost surely, 2^21749170576 is an apocalyptic number.

21749170576 is the 147476-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21749170576

21749170576 is an abundant number, since it is smaller than the sum of its proper divisors (29718349745).

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

21749170576 is an equidigital number, since it uses as much as digits as its factorization.

21749170576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 740880, while the sum is 49.

Multiplying 21749170576 by its sum of digits (49), we get a square (1065709358224 = 1032332²).

21749170576 divided by its sum of digits (49) gives a square (443860624 = 21068²).

The spelling of 21749170576 in words is "twenty-one billion, seven hundred forty-nine million, one hundred seventy thousand, five hundred seventy-six".