70512721 has 2 divisors, whose sum is σ = 70512722. Its totient is φ = 70512720.

The previous prime is 70512707. The next prime is 70512749. The reversal of 70512721 is 12721507.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69072721 + 1440000 = 8311^2 + 1200^2 .

It is a cyclic number.

It is not a de Polignac number, because 70512721 - 2⁷ = 70512593 is a prime.

It is not a weakly prime, because it can be changed into another prime (70512521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35256360 + 35256361.

It is an arithmetic number, because the mean of its divisors is an integer number (35256361).

Almost surely, 2^70512721 is an apocalyptic number.

It is an amenable number.

70512721 is a deficient number, since it is larger than the sum of its proper divisors (1).

70512721 is an equidigital number, since it uses as much as digits as its factorization.

70512721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 70512721 is about 8397.1853022307. The cubic root of 70512721 is about 413.1323067867.

The spelling of 70512721 in words is "seventy million, five hundred twelve thousand, seven hundred twenty-one".