64099721 has 8 divisors (see below), whose sum is σ = 73667520. Its totient is φ = 54634608.

The previous prime is 64099699. The next prime is 64099727. The reversal of 64099721 is 12799046.

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

It is not a de Polignac number, because 64099721 - 2¹⁴ = 64083337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64099727) 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, 24326 + ... + 26831.

It is an arithmetic number, because the mean of its divisors is an integer number (9208440).

Almost surely, 2^64099721 is an apocalyptic number.

It is an amenable number.

64099721 is a deficient number, since it is larger than the sum of its proper divisors (9567799).

64099721 is a wasteful number, since it uses less digits than its factorization.

64099721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51343.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 64099721 is about 8006.2301365874. The cubic root of 64099721 is about 400.2076442743.

The spelling of 64099721 in words is "sixty-four million, ninety-nine thousand, seven hundred twenty-one".