721785064 has 128 divisors (see below), whose sum is σ = 1831092480. Its totient is φ = 257587200.

The previous prime is 721785041. The next prime is 721785079. The reversal of 721785064 is 460587127.

It is a super-2 number, since 2×721785064² = 1041947357226968192, which contains 22 as substring.

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, 1385124 + ... + 1385644.

It is an arithmetic number, because the mean of its divisors is an integer number (14305410).

Almost surely, 2^721785064 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 721785064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (915546240).

721785064 is an abundant number, since it is smaller than the sum of its proper divisors (1109307416).

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

721785064 is a wasteful number, since it uses less digits than its factorization.

721785064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731 (or 727 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 40.

The square root of 721785064 is about 26866.0578425641. The cubic root of 721785064 is about 897.0210411967.

The spelling of 721785064 in words is "seven hundred twenty-one million, seven hundred eighty-five thousand, sixty-four".