64642951 has 4 divisors (see below), whose sum is σ = 64849792. Its totient is φ = 64436112.

The previous prime is 64642939. The next prime is 64642969. The reversal of 64642951 is 15924646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64642951 is a prime.

It is a super-2 number, since 2×64642951² = 8357422227976802, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64642951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64642931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102951 + ... + 103576.

It is an arithmetic number, because the mean of its divisors is an integer number (16212448).

Almost surely, 2^64642951 is an apocalyptic number.

64642951 is a deficient number, since it is larger than the sum of its proper divisors (206841).

64642951 is a wasteful number, since it uses less digits than its factorization.

64642951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206840.

The product of its digits is 51840, while the sum is 37.

The square root of 64642951 is about 8040.0840169740. The cubic root of 64642951 is about 401.3350205930.

The spelling of 64642951 in words is "sixty-four million, six hundred forty-two thousand, nine hundred fifty-one".