64532721 has 24 divisors (see below), whose sum is σ = 99084384. Its totient is φ = 37045440.

The previous prime is 64532711. The next prime is 64532737. The reversal of 64532721 is 12723546.

It is not a de Polignac number, because 64532721 - 2⁷ = 64532593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64532701) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9205 + ... + 14621.

It is an arithmetic number, because the mean of its divisors is an integer number (4128516).

Almost surely, 2^64532721 is an apocalyptic number.

It is an amenable number.

64532721 is a deficient number, since it is larger than the sum of its proper divisors (34551663).

64532721 is a wasteful number, since it uses less digits than its factorization.

64532721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5469 (or 5450 counting only the distinct ones).

The product of its digits is 10080, while the sum is 30.

The square root of 64532721 is about 8033.2260642907. The cubic root of 64532721 is about 401.1067702413.

The spelling of 64532721 in words is "sixty-four million, five hundred thirty-two thousand, seven hundred twenty-one".