726664320 has 384 divisors, whose sum is σ = 2736704880. Its totient is φ = 176947200.

The previous prime is 726664313. The next prime is 726664331. The reversal of 726664320 is 23466627.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 41062464 + 685601856 = 6408^2 + 26184^2 .

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×726664320² = 1056082067922124800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4014630 + ... + 4014810.

Almost surely, 2^726664320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 726664320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1368352440).

726664320 is an abundant number, since it is smaller than the sum of its proper divisors (2010040560).

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

726664320 is a wasteful number, since it uses less digits than its factorization.

726664320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 726664320 is about 26956.7119656682. The cubic root of 726664320 is about 899.0377864538.

The spelling of 726664320 in words is "seven hundred twenty-six million, six hundred sixty-four thousand, three hundred twenty".