64681257 has 8 divisors (see below), whose sum is σ = 86371776. Its totient is φ = 43055792.

The previous prime is 64681247. The next prime is 64681261. The reversal of 64681257 is 75218646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64681257 - 2⁴ = 64681241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64681247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13893 + ... + 17954.

It is an arithmetic number, because the mean of its divisors is an integer number (10796472).

Almost surely, 2^64681257 is an apocalyptic number.

It is an amenable number.

64681257 is a deficient number, since it is larger than the sum of its proper divisors (21690519).

64681257 is a wasteful number, since it uses less digits than its factorization.

64681257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32527.

The product of its digits is 80640, while the sum is 39.

The square root of 64681257 is about 8042.4658532070. The cubic root of 64681257 is about 401.4142790601.

The spelling of 64681257 in words is "sixty-four million, six hundred eighty-one thousand, two hundred fifty-seven".