64397986 has 4 divisors (see below), whose sum is σ = 96596982. Its totient is φ = 32198992.

The previous prime is 64397981. The next prime is 64397987. The reversal of 64397986 is 68979346.

64397986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 63504961 + 893025 = 7969^2 + 945^2 .

It is not an unprimeable number, because it can be changed into a prime (64397981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16099495 + ... + 16099498.

Almost surely, 2^64397986 is an apocalyptic number.

64397986 is a deficient number, since it is larger than the sum of its proper divisors (32198996).

64397986 is a wasteful number, since it uses less digits than its factorization.

64397986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32198995.

The product of its digits is 1959552, while the sum is 52.

The square root of 64397986 is about 8024.8355746395. The cubic root of 64397986 is about 400.8274247406.

The spelling of 64397986 in words is "sixty-four million, three hundred ninety-seven thousand, nine hundred eighty-six".