721624873 has 2 divisors, whose sum is σ = 721624874. Its totient is φ = 721624872.

The previous prime is 721624861. The next prime is 721624973. The reversal of 721624873 is 378426127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 496264729 + 225360144 = 22277^2 + 15012^2 .

It is a cyclic number.

It is not a de Polignac number, because 721624873 - 2¹³ = 721616681 is a prime.

It is a super-2 number, since 2×721624873² = 1041484914664532258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721624273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360812436 + 360812437.

It is an arithmetic number, because the mean of its divisors is an integer number (360812437).

Almost surely, 2^721624873 is an apocalyptic number.

It is an amenable number.

721624873 is a deficient number, since it is larger than the sum of its proper divisors (1).

721624873 is an equidigital number, since it uses as much as digits as its factorization.

721624873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 40.

The square root of 721624873 is about 26863.0763874877. The cubic root of 721624873 is about 896.9546754891.

The spelling of 721624873 in words is "seven hundred twenty-one million, six hundred twenty-four thousand, eight hundred seventy-three".