645152722721 has 8 divisors (see below), whose sum is σ = 731347216320. Its totient is φ = 564182137872.

The previous prime is 645152722691. The next prime is 645152722741. The reversal of 645152722721 is 127227251546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645152722721 - 2³⁴ = 627972853537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645152722741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1305976925 + ... + 1305977418.

It is an arithmetic number, because the mean of its divisors is an integer number (91418402040).

Almost surely, 2^645152722721 is an apocalyptic number.

It is an amenable number.

645152722721 is a deficient number, since it is larger than the sum of its proper divisors (86194493599).

645152722721 is a wasteful number, since it uses less digits than its factorization.

645152722721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2611954375.

The product of its digits is 470400, while the sum is 44.

The spelling of 645152722721 in words is "six hundred forty-five billion, one hundred fifty-two million, seven hundred twenty-two thousand, seven hundred twenty-one".