721147505634 has 12 divisors (see below), whose sum is σ = 1562486262246. Its totient is φ = 240382501872.

The previous prime is 721147505563. The next prime is 721147505641. The reversal of 721147505634 is 436505741127.

721147505634 is a `hidden beast` number, since 7 + 2 + 1 + 1 + 4 + 7 + 5 + 0 + 5 + 634 = 666.

It can be written as a sum of positive squares in only one way, i.e., 543320832609 + 177826673025 = 737103^2 + 421695^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 721147505634.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 20031875139 + ... + 20031875174.

Almost surely, 2^721147505634 is an apocalyptic number.

721147505634 is an abundant number, since it is smaller than the sum of its proper divisors (841338756612).

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

721147505634 is a wasteful number, since it uses less digits than its factorization.

721147505634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40063750321 (or 40063750318 counting only the distinct ones).

The product of its (nonzero) digits is 705600, while the sum is 45.

The spelling of 721147505634 in words is "seven hundred twenty-one billion, one hundred forty-seven million, five hundred five thousand, six hundred thirty-four".