70917521 has 2 divisors, whose sum is σ = 70917522. Its totient is φ = 70917520.

The previous prime is 70917503. The next prime is 70917527. The reversal of 70917521 is 12571907.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48497296 + 22420225 = 6964^2 + 4735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70917521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (70917527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35458760 + 35458761.

It is an arithmetic number, because the mean of its divisors is an integer number (35458761).

Almost surely, 2^70917521 is an apocalyptic number.

It is an amenable number.

70917521 is a deficient number, since it is larger than the sum of its proper divisors (1).

70917521 is an equidigital number, since it uses as much as digits as its factorization.

70917521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4410, while the sum is 32.

The square root of 70917521 is about 8421.2541227539. The cubic root of 70917521 is about 413.9213698522.

The spelling of 70917521 in words is "seventy million, nine hundred seventeen thousand, five hundred twenty-one".