64911521 has 2 divisors, whose sum is σ = 64911522. Its totient is φ = 64911520.

The previous prime is 64911499. The next prime is 64911533. The reversal of 64911521 is 12511946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56851600 + 8059921 = 7540^2 + 2839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64911521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (64911421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32455760 + 32455761.

It is an arithmetic number, because the mean of its divisors is an integer number (32455761).

Almost surely, 2^64911521 is an apocalyptic number.

It is an amenable number.

64911521 is a deficient number, since it is larger than the sum of its proper divisors (1).

64911521 is an equidigital number, since it uses as much as digits as its factorization.

64911521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 29.

The square root of 64911521 is about 8056.7686450586. The cubic root of 64911521 is about 401.8900572261.

The spelling of 64911521 in words is "sixty-four million, nine hundred eleven thousand, five hundred twenty-one".