15961840440 has 384 divisors, whose sum is σ = 59639846400. Its totient is φ = 3346237440.

The previous prime is 15961840373. The next prime is 15961840457. The reversal of 15961840440 is 4404816951.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 15961840392 and 15961840401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 32508595 + ... + 32509085.

It is an arithmetic number, because the mean of its divisors is an integer number (155312100).

Almost surely, 2^15961840440 is an apocalyptic number.

15961840440 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 15961840440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29819923200).

15961840440 is an abundant number, since it is smaller than the sum of its proper divisors (43678005960).

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

15961840440 is a wasteful number, since it uses less digits than its factorization.

15961840440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767 (or 750 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 15961840440 in words is "fifteen billion, nine hundred sixty-one million, eight hundred forty thousand, four hundred forty".