64508721 has 8 divisors (see below), whose sum is σ = 89751360. Its totient is φ = 41135952.

The previous prime is 64508701. The next prime is 64508747. The reversal of 64508721 is 12780546.

64508721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64508721 - 2¹³ = 64500529 is a prime.

It is a super-2 number, since 2×64508721² = 8322750170111682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64508701) 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 in 7 ways as a sum of consecutive naturals, for example, 467386 + ... + 467523.

It is an arithmetic number, because the mean of its divisors is an integer number (11218920).

Almost surely, 2^64508721 is an apocalyptic number.

It is an amenable number.

64508721 is a deficient number, since it is larger than the sum of its proper divisors (25242639).

64508721 is a wasteful number, since it uses less digits than its factorization.

64508721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934935.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 64508721 is about 8031.7321294973. The cubic root of 64508721 is about 401.0570396242.

The spelling of 64508721 in words is "sixty-four million, five hundred eight thousand, seven hundred twenty-one".