870423721 has 2 divisors, whose sum is σ = 870423722. Its totient is φ = 870423720.

The previous prime is 870423689. The next prime is 870423761. The reversal of 870423721 is 127324078.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649485225 + 220938496 = 25485^2 + 14864^2 .

It is a cyclic number.

It is not a de Polignac number, because 870423721 - 2⁵ = 870423689 is a prime.

It is not a weakly prime, because it can be changed into another prime (870423761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 435211860 + 435211861.

It is an arithmetic number, because the mean of its divisors is an integer number (435211861).

Almost surely, 2^870423721 is an apocalyptic number.

It is an amenable number.

870423721 is a deficient number, since it is larger than the sum of its proper divisors (1).

870423721 is an equidigital number, since it uses as much as digits as its factorization.

870423721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 870423721 is about 29502.9442768006. The cubic root of 870423721 is about 954.7952270583.

Adding to 870423721 its reverse (127324078), we get a palindrome (997747799).

The spelling of 870423721 in words is "eight hundred seventy million, four hundred twenty-three thousand, seven hundred twenty-one".