15721255120 has 80 divisors (see below), whose sum is σ = 38502000000. Its totient is φ = 5953457664.

The previous prime is 15721255117. The next prime is 15721255129. The reversal of 15721255120 is 2155212751.

It is a happy number.

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 (15721255129) 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, 3142381 + ... + 3147379.

It is an arithmetic number, because the mean of its divisors is an integer number (481275000).

Almost surely, 2^15721255120 is an apocalyptic number.

15721255120 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 15721255120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19251000000).

15721255120 is an abundant number, since it is smaller than the sum of its proper divisors (22780744880).

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

15721255120 is a wasteful number, since it uses less digits than its factorization.

15721255120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7100 (or 7094 counting only the distinct ones).

The product of its (nonzero) digits is 7000, while the sum is 31.

Adding to 15721255120 its reverse (2155212751), we get a palindrome (17876467871).

The spelling of 15721255120 in words is "fifteen billion, seven hundred twenty-one million, two hundred fifty-five thousand, one hundred twenty".