64215869 has 2 divisors, whose sum is σ = 64215870. Its totient is φ = 64215868.

The previous prime is 64215857. The next prime is 64215883. The reversal of 64215869 is 96851246.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63840100 + 375769 = 7990^2 + 613^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64215869 is a prime.

It is a super-2 number, since 2×64215869² = 8247355662850322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64215829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32107934 + 32107935.

It is an arithmetic number, because the mean of its divisors is an integer number (32107935).

Almost surely, 2^64215869 is an apocalyptic number.

It is an amenable number.

64215869 is a deficient number, since it is larger than the sum of its proper divisors (1).

64215869 is an equidigital number, since it uses as much as digits as its factorization.

64215869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 64215869 is about 8013.4804548336. The cubic root of 64215869 is about 400.4492223926.

The spelling of 64215869 in words is "sixty-four million, two hundred fifteen thousand, eight hundred sixty-nine".