68913521 has 2 divisors, whose sum is σ = 68913522. Its totient is φ = 68913520.

The previous prime is 68913511. The next prime is 68913547. The reversal of 68913521 is 12531986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37149025 + 31764496 = 6095^2 + 5636^2 .

It is a cyclic number.

It is not a de Polignac number, because 68913521 - 2²⁶ = 1804657 is a prime.

It is not a weakly prime, because it can be changed into another prime (68913511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34456760 + 34456761.

It is an arithmetic number, because the mean of its divisors is an integer number (34456761).

Almost surely, 2^68913521 is an apocalyptic number.

It is an amenable number.

68913521 is a deficient number, since it is larger than the sum of its proper divisors (1).

68913521 is an equidigital number, since it uses as much as digits as its factorization.

68913521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 68913521 is about 8301.4168067867. The cubic root of 68913521 is about 409.9851690055.

The spelling of 68913521 in words is "sixty-eight million, nine hundred thirteen thousand, five hundred twenty-one".