15661055020 has 96 divisors (see below), whose sum is σ = 36704041920. Its totient is φ = 5573299200.

The previous prime is 15661055017. The next prime is 15661055021. The reversal of 15661055020 is 2055016651.

It is not an unprimeable number, because it can be changed into a prime (15661055021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5284059 + ... + 5287021.

It is an arithmetic number, because the mean of its divisors is an integer number (382333770).

Almost surely, 2^15661055020 is an apocalyptic number.

15661055020 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 15661055020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18352020960).

15661055020 is an abundant number, since it is smaller than the sum of its proper divisors (21042986900).

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

15661055020 is a wasteful number, since it uses less digits than its factorization.

15661055020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3715 (or 3713 counting only the distinct ones).

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

The spelling of 15661055020 in words is "fifteen billion, six hundred sixty-one million, fifty-five thousand, twenty".