64021686 has 16 divisors (see below), whose sum is σ = 128226864. Its totient is φ = 21309984.

The previous prime is 64021681. The next prime is 64021687. The reversal of 64021686 is 68612046.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64021681) 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, 2881 + ... + 11676.

It is an arithmetic number, because the mean of its divisors is an integer number (8014179).

Almost surely, 2^64021686 is an apocalyptic number.

64021686 is an abundant number, since it is smaller than the sum of its proper divisors (64205178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64021686 is a wasteful number, since it uses less digits than its factorization.

64021686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15295.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 64021686 is about 8001.3552602044. The cubic root of 64021686 is about 400.0451740647.

The spelling of 64021686 in words is "sixty-four million, twenty-one thousand, six hundred eighty-six".