15985220000 has 120 divisors (see below), whose sum is σ = 39414161556. Its totient is φ = 6379776000.

The previous prime is 15985219981. The next prime is 15985220057. The reversal of 15985220000 is 2258951.

It can be written as a sum of positive squares in 10 ways, for example, as 8737762576 + 7247457424 = 93476^2 + 85132^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17059532 + ... + 17060468.

Almost surely, 2^15985220000 is an apocalyptic number.

15985220000 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 15985220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19707080778).

15985220000 is an abundant number, since it is smaller than the sum of its proper divisors (23428941556).

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

15985220000 is an frugal number, since it uses more digits than its factorization.

15985220000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820 (or 1797 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

Adding to 15985220000 its reverse (2258951), we get a palindrome (15987478951).

The spelling of 15985220000 in words is "fifteen billion, nine hundred eighty-five million, two hundred twenty thousand".