20156743751531 has 8 divisors (see below), whose sum is σ = 20358188314464. Its totient is φ = 19955409727680.

The previous prime is 20156743751479. The next prime is 20156743751533. The reversal of 20156743751531 is 13515734765102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20156743751531 is a prime.

It is a super-3 number, since 3×20156743751531³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 20156743751531.

It is not an unprimeable number, because it can be changed into a prime (20156743751533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27268226 + ... + 27997671.

It is an arithmetic number, because the mean of its divisors is an integer number (2544773539308).

Almost surely, 2^{20156743751531} is an apocalyptic number.

20156743751531 is a deficient number, since it is larger than the sum of its proper divisors (201444562933).

20156743751531 is a wasteful number, since it uses less digits than its factorization.

20156743751531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55269541.

The product of its (nonzero) digits is 2646000, while the sum is 50.

The spelling of 20156743751531 in words is "twenty trillion, one hundred fifty-six billion, seven hundred forty-three million, seven hundred fifty-one thousand, five hundred thirty-one".