721364646 has 32 divisors (see below), whose sum is σ = 1480026240. Its totient is φ = 234267264.

The previous prime is 721364641. The next prime is 721364681. The reversal of 721364646 is 646463127.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721364641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104766 + ... + 111438.

It is an arithmetic number, because the mean of its divisors is an integer number (46250820).

Almost surely, 2^721364646 is an apocalyptic number.

721364646 is an abundant number, since it is smaller than the sum of its proper divisors (758661594).

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

721364646 is a wasteful number, since it uses less digits than its factorization.

721364646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7140.

The product of its digits is 145152, while the sum is 39.

The square root of 721364646 is about 26858.2323692383. The cubic root of 721364646 is about 896.8468448162.

The spelling of 721364646 in words is "seven hundred twenty-one million, three hundred sixty-four thousand, six hundred forty-six".