64216261 has 2 divisors, whose sum is σ = 64216262. Its totient is φ = 64216260.

The previous prime is 64216247. The next prime is 64216279. The reversal of 64216261 is 16261246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45562500 + 18653761 = 6750^2 + 4319^2 .

It is a cyclic number.

It is not a de Polignac number, because 64216261 - 2⁷ = 64216133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64216961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32108130 + 32108131.

It is an arithmetic number, because the mean of its divisors is an integer number (32108131).

Almost surely, 2^64216261 is an apocalyptic number.

It is an amenable number.

64216261 is a deficient number, since it is larger than the sum of its proper divisors (1).

64216261 is an equidigital number, since it uses as much as digits as its factorization.

64216261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 28.

The square root of 64216261 is about 8013.5049135818. The cubic root of 64216261 is about 400.4500372263.

The spelling of 64216261 in words is "sixty-four million, two hundred sixteen thousand, two hundred sixty-one".