15561995271680 has 1280 divisors, whose sum is σ = 47305772236800. Its totient is φ = 4825827901440.

The previous prime is 15561995271677. The next prime is 15561995271701. The reversal of 15561995271680 is 8617259916551.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (65).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 69784732049 + ... + 69784732271.

It is an arithmetic number, because the mean of its divisors is an integer number (36957634560).

Almost surely, 2^{15561995271680} is an apocalyptic number.

15561995271680 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 15561995271680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23652886118400).

15561995271680 is an abundant number, since it is smaller than the sum of its proper divisors (31743776965120).

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

15561995271680 is a wasteful number, since it uses less digits than its factorization.

15561995271680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495 (or 479 counting only the distinct ones).

The product of its (nonzero) digits is 40824000, while the sum is 65.

The spelling of 15561995271680 in words is "fifteen trillion, five hundred sixty-one billion, nine hundred ninety-five million, two hundred seventy-one thousand, six hundred eighty".