721254660 has 96 divisors (see below), whose sum is σ = 2316287232. Its totient is φ = 164267520.

The previous prime is 721254659. The next prime is 721254683. The reversal of 721254660 is 66452127.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 120130 + ... + 125990.

It is an arithmetic number, because the mean of its divisors is an integer number (24127992).

Almost surely, 2^721254660 is an apocalyptic number.

721254660 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721254660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1158143616).

721254660 is an abundant number, since it is smaller than the sum of its proper divisors (1595032572).

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

721254660 is a wasteful number, since it uses less digits than its factorization.

721254660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6173 (or 6171 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 33.

The square root of 721254660 is about 26856.1847625459. The cubic root of 721254660 is about 896.8012619471.

The spelling of 721254660 in words is "seven hundred twenty-one million, two hundred fifty-four thousand, six hundred sixty".