15805135380551 has 4 divisors (see below), whose sum is σ = 17241965869704. Its totient is φ = 14368304891400.

The previous prime is 15805135380533. The next prime is 15805135380553. The reversal of 15805135380551 is 15508353150851.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15805135380551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15805135380551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15805135380553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 718415244560 + ... + 718415244581.

It is an arithmetic number, because the mean of its divisors is an integer number (4310491467426).

Almost surely, 2^{15805135380551} is an apocalyptic number.

15805135380551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

15805135380551 is a deficient number, since it is larger than the sum of its proper divisors (1436830489153).

15805135380551 is a wasteful number, since it uses less digits than its factorization.

15805135380551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1436830489152.

The product of its (nonzero) digits is 1800000, while the sum is 50.

The spelling of 15805135380551 in words is "fifteen trillion, eight hundred five billion, one hundred thirty-five million, three hundred eighty thousand, five hundred fifty-one".