15990172640 has 96 divisors (see below), whose sum is σ = 41629031136. Its totient is φ = 5766727680.

The previous prime is 15990172619. The next prime is 15990172643. The reversal of 15990172640 is 4627109951.

It is a junction number, because it is equal to n+sod(n) for n = 15990172591 and 15990172600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15990172643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50 + ... + 178830.

It is an arithmetic number, because the mean of its divisors is an integer number (433635741).

Almost surely, 2^15990172640 is an apocalyptic number.

15990172640 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 15990172640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20814515568).

15990172640 is an abundant number, since it is smaller than the sum of its proper divisors (25638858496).

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

15990172640 is a wasteful number, since it uses less digits than its factorization.

15990172640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178852 (or 178844 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 44.

The spelling of 15990172640 in words is "fifteen billion, nine hundred ninety million, one hundred seventy-two thousand, six hundred forty".