15611781120 has 448 divisors, whose sum is σ = 55817536320. Its totient is φ = 3699376128.

The previous prime is 15611781113. The next prime is 15611781121. The reversal of 15611781120 is 2118711651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15611781121) 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, 46325592 + ... + 46325928.

It is an arithmetic number, because the mean of its divisors is an integer number (124592715).

Almost surely, 2^15611781120 is an apocalyptic number.

15611781120 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 15611781120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27908768160).

15611781120 is an abundant number, since it is smaller than the sum of its proper divisors (40205755200).

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

15611781120 is a wasteful number, since it uses less digits than its factorization.

15611781120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 33.

The spelling of 15611781120 in words is "fifteen billion, six hundred eleven million, seven hundred eighty-one thousand, one hundred twenty".