970621721 has 2 divisors, whose sum is σ = 970621722. Its totient is φ = 970621720.

The previous prime is 970621693. The next prime is 970621723. The reversal of 970621721 is 127126079.

970621721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490135321 + 480486400 = 22139^2 + 21920^2 .

It is a cyclic number.

It is not a de Polignac number, because 970621721 - 2⁶ = 970621657 is a prime.

Together with 970621723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (970621723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485310860 + 485310861.

It is an arithmetic number, because the mean of its divisors is an integer number (485310861).

Almost surely, 2^970621721 is an apocalyptic number.

It is an amenable number.

970621721 is a deficient number, since it is larger than the sum of its proper divisors (1).

970621721 is an equidigital number, since it uses as much as digits as its factorization.

970621721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 970621721 is about 31154.8025350828. The cubic root of 970621721 is about 990.1097456816.

The spelling of 970621721 in words is "nine hundred seventy million, six hundred twenty-one thousand, seven hundred twenty-one".