15552661 has 4 divisors (see below), whose sum is σ = 15727500. Its totient is φ = 15377824.

The previous prime is 15552631. The next prime is 15552679. The reversal of 15552661 is 16625551.

15552661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11015761 + 4536900 = 3319^2 + 2130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15552661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15552601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87286 + ... + 87463.

It is an arithmetic number, because the mean of its divisors is an integer number (3931875).

Almost surely, 2^15552661 is an apocalyptic number.

It is an amenable number.

15552661 is a deficient number, since it is larger than the sum of its proper divisors (174839).

15552661 is an equidigital number, since it uses as much as digits as its factorization.

15552661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174838.

The product of its digits is 9000, while the sum is 31.

The square root of 15552661 is about 3943.6862197695. The cubic root of 15552661 is about 249.6135950726.

The spelling of 15552661 in words is "fifteen million, five hundred fifty-two thousand, six hundred sixty-one".