64721616 has 40 divisors (see below), whose sum is σ = 171280704. Its totient is φ = 21047040.

The previous prime is 64721611. The next prime is 64721617. The reversal of 64721616 is 61612746.

It is a super-3 number, since 3×64721616³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64721611) 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, 14476 + ... + 18411.

Almost surely, 2^64721616 is an apocalyptic number.

It is an amenable number.

64721616 is an abundant number, since it is smaller than the sum of its proper divisors (106559088).

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

64721616 is a wasteful number, since it uses less digits than its factorization.

64721616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32939 (or 32933 counting only the distinct ones).

The product of its digits is 12096, while the sum is 33.

The square root of 64721616 is about 8044.9745804446. The cubic root of 64721616 is about 401.4977515180.

The spelling of 64721616 in words is "sixty-four million, seven hundred twenty-one thousand, six hundred sixteen".