721875 has 48 divisors (see below), whose sum is σ = 1499904. Its totient is φ = 300000.

The previous prime is 721859. The next prime is 721883. The reversal of 721875 is 578127.

It is a happy number.

721875 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 721875 - 2⁴ = 721859 is a prime.

It is a super-2 number, since 2×721875² = 1042207031250, which contains 22 as substring.

It is a congruent number.

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, 65620 + ... + 65630.

It is an arithmetic number, because the mean of its divisors is an integer number (31248).

2⁷²¹⁸⁷⁵ is an apocalyptic number.

721875 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

721875 is an abundant number, since it is smaller than the sum of its proper divisors (778029).

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

721875 is an equidigital number, since it uses as much as digits as its factorization.

721875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46 (or 26 counting only the distinct ones).

The product of its digits is 3920, while the sum is 30.

The square root of 721875 is about 849.6322733983. The cubic root of 721875 is about 89.7058296578.

It can be divided in two parts, 721 and 875, that added together give a triangular number (1596 = T₅₆).

The spelling of 721875 in words is "seven hundred twenty-one thousand, eight hundred seventy-five".