15220864 has 16 divisors (see below), whose sum is σ = 30323070. Its totient is φ = 7610368.

The previous prime is 15220861. The next prime is 15220867. The reversal of 15220864 is 46802251.

It is an interprime number because it is at equal distance from previous prime (15220861) and next prime (15220867).

It can be written as a sum of positive squares in only one way, i.e., 15054400 + 166464 = 3880^2 + 408^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (15220861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59329 + ... + 59584.

Almost surely, 2^15220864 is an apocalyptic number.

It is an amenable number.

15220864 is a deficient number, since it is larger than the sum of its proper divisors (15102206).

15220864 is an equidigital number, since it uses as much as digits as its factorization.

15220864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118927 (or 118915 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 15220864 is about 3901.3925718902. The cubic root of 15220864 is about 247.8257534256.

The spelling of 15220864 in words is "fifteen million, two hundred twenty thousand, eight hundred sixty-four".