64721406 has 16 divisors (see below), whose sum is σ = 130725648. Its totient is φ = 21360000.

The previous prime is 64721383. The next prime is 64721441. The reversal of 64721406 is 60412746.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52795 + ... + 54006.

It is an arithmetic number, because the mean of its divisors is an integer number (8170353).

Almost surely, 2^64721406 is an apocalyptic number.

64721406 is an abundant number, since it is smaller than the sum of its proper divisors (66004242).

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

64721406 is a wasteful number, since it uses less digits than its factorization.

64721406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106907.

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 64721406 is about 8044.9615288080. The cubic root of 64721406 is about 401.4973172755.

The spelling of 64721406 in words is "sixty-four million, seven hundred twenty-one thousand, four hundred six".