21723556450 has 12 divisors (see below), whose sum is σ = 40405815090. Its totient is φ = 8689422560.

The previous prime is 21723556427. The next prime is 21723556451. The reversal of 21723556450 is 5465532712.

It can be written as a sum of positive squares in 3 ways, for example, as 12073834161 + 9649722289 = 109881^2 + 98233^2 .

It is not an unprimeable number, because it can be changed into a prime (21723556451) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 217235515 + ... + 217235614.

Almost surely, 2^21723556450 is an apocalyptic number.

21723556450 is a deficient number, since it is larger than the sum of its proper divisors (18682258640).

21723556450 is a wasteful number, since it uses less digits than its factorization.

21723556450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434471141 (or 434471136 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 40.

The spelling of 21723556450 in words is "twenty-one billion, seven hundred twenty-three million, five hundred fifty-six thousand, four hundred fifty".