721745492 has 12 divisors (see below), whose sum is σ = 1360212756. Its totient is φ = 333113280.

The previous prime is 721745491. The next prime is 721745537. The reversal of 721745492 is 294547127.

It can be written as a sum of positive squares in 2 ways, for example, as 488144836 + 233600656 = 22094^2 + 15284^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721745491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6939809 + ... + 6939912.

It is an arithmetic number, because the mean of its divisors is an integer number (113351063).

Almost surely, 2^721745492 is an apocalyptic number.

It is an amenable number.

721745492 is a deficient number, since it is larger than the sum of its proper divisors (638467264).

721745492 is a wasteful number, since it uses less digits than its factorization.

721745492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13879738 (or 13879736 counting only the distinct ones).

The product of its digits is 141120, while the sum is 41.

The square root of 721745492 is about 26865.3213641676. The cubic root of 721745492 is about 897.0046477821.

The spelling of 721745492 in words is "seven hundred twenty-one million, seven hundred forty-five thousand, four hundred ninety-two".