15991120000 has 80 divisors (see below), whose sum is σ = 39809092950. Its totient is φ = 6396416000.

The previous prime is 15991119971. The next prime is 15991120003. The reversal of 15991120000 is 2119951.

It can be written as a sum of positive squares in 5 ways, for example, as 64 + 15991119936 = 8^2 + 126456^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15991120003) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 19945 + ... + 179944.

Almost surely, 2^15991120000 is an apocalyptic number.

15991120000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15991120000 is an abundant number, since it is smaller than the sum of its proper divisors (23817972950).

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

15991120000 is an frugal number, since it uses more digits than its factorization.

15991120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199923 (or 199896 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 28.

Adding to 15991120000 its reverse (2119951), we get a palindrome (15993239951).

The spelling of 15991120000 in words is "fifteen billion, nine hundred ninety-one million, one hundred twenty thousand".