721705464 has 160 divisors (see below), whose sum is σ = 2108304000. Its totient is φ = 230465088.

The previous prime is 721705429. The next prime is 721705469. The reversal of 721705464 is 464507127.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721705469) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1643757 + ... + 1644195.

It is an arithmetic number, because the mean of its divisors is an integer number (13176900).

Almost surely, 2^721705464 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 721705464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1054152000).

721705464 is an abundant number, since it is smaller than the sum of its proper divisors (1386598536).

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

721705464 is a wasteful number, since it uses less digits than its factorization.

721705464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559 (or 546 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 721705464 is about 26864.5763785696. The cubic root of 721705464 is about 896.9880648517.

The spelling of 721705464 in words is "seven hundred twenty-one million, seven hundred five thousand, four hundred sixty-four".