721801125 has 84 divisors (see below), whose sum is σ = 1365939588. Its totient is φ = 380635200.

The previous prime is 721801121. The next prime is 721801163. The reversal of 721801125 is 521108127.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 6 ways, for example, as 468895716 + 252905409 = 21654^2 + 15903^2 .

It is not a de Polignac number, because 721801125 - 2² = 721801121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721801121) by changing a digit.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 8110081 + ... + 8110169.

Almost surely, 2^721801125 is an apocalyptic number.

721801125 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

It is an amenable number.

721801125 is a deficient number, since it is larger than the sum of its proper divisors (644138463).

721801125 is an frugal number, since it uses more digits than its factorization.

721801125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 721801125 is about 26866.3567496600. The cubic root of 721801125 is about 897.0276945846.

The spelling of 721801125 in words is "seven hundred twenty-one million, eight hundred one thousand, one hundred twenty-five".