15561611000 has 128 divisors (see below), whose sum is σ = 39385906560. Its totient is φ = 5720832000.

The previous prime is 15561610993. The next prime is 15561611027. The reversal of 15561611000 is 11616551.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3130517 + ... + 3135483.

It is an arithmetic number, because the mean of its divisors is an integer number (307702395).

Almost surely, 2^15561611000 is an apocalyptic number.

15561611000 is a gapful number since it is divisible by the number (10) 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 15561611000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19692953280).

15561611000 is an abundant number, since it is smaller than the sum of its proper divisors (23824295560).

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

15561611000 is a wasteful number, since it uses less digits than its factorization.

15561611000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5242 (or 5228 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 26.

The spelling of 15561611000 in words is "fifteen billion, five hundred sixty-one million, six hundred eleven thousand".