15131971971720 has 256 divisors, whose sum is σ = 52572517171200. Its totient is φ = 3867111279360.

The previous prime is 15131971971583. The next prime is 15131971971737. The reversal of 15131971971720 is 2717917913151.

15131971971720 is a `hidden beast` number, since 1 + 5 + 1 + 319 + 71 + 97 + 172 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1254409 + ... + 5642471.

It is an arithmetic number, because the mean of its divisors is an integer number (205361395200).

Almost surely, 2^{15131971971720} is an apocalyptic number.

15131971971720 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 15131971971720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26286258585600).

15131971971720 is an abundant number, since it is smaller than the sum of its proper divisors (37440545199480).

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

15131971971720 is a wasteful number, since it uses less digits than its factorization.

15131971971720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4388217 (or 4388207 counting only the distinct ones).

The product of its (nonzero) digits is 833490, while the sum is 54.

The spelling of 15131971971720 in words is "fifteen trillion, one hundred thirty-one billion, nine hundred seventy-one million, nine hundred seventy-one thousand, seven hundred twenty".