15561648 has 60 divisors (see below), whose sum is σ = 44394480. Its totient is φ = 5086848.

The previous prime is 15561641. The next prime is 15561671. The reversal of 15561648 is 84616551.

15561648 is a `hidden beast` number, since 1 + 5 + 5 + 6 + 1 + 648 = 666.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (15561641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6613 + ... + 8651.

It is an arithmetic number, because the mean of its divisors is an integer number (739908).

Almost surely, 2^15561648 is an apocalyptic number.

15561648 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15561648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22197240).

15561648 is an abundant number, since it is smaller than the sum of its proper divisors (28832832).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15561648 is a wasteful number, since it uses less digits than its factorization.

15561648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2106 (or 2097 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 15561648 is about 3944.8254714246. The cubic root of 15561648 is about 249.6616649909.

The spelling of 15561648 in words is "fifteen million, five hundred sixty-one thousand, six hundred forty-eight".