161291951481 has 8 divisors (see below), whose sum is σ = 216136619200. Its totient is φ = 106987625712.

The previous prime is 161291951479. The next prime is 161291951497. The reversal of 161291951481 is 184159192161.

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

It is not a de Polignac number, because 161291951481 - 2¹ = 161291951479 is a prime.

It is a super-2 number, since 2×161291951481² (a number of 23 digits) contains 22 as substring.

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 161291951481.

It is not an unprimeable number, because it can be changed into a prime (161291951461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135084790 + ... + 135085983.

It is an arithmetic number, because the mean of its divisors is an integer number (27017077400).

Almost surely, 2^161291951481 is an apocalyptic number.

It is an amenable number.

161291951481 is a deficient number, since it is larger than the sum of its proper divisors (54844667719).

161291951481 is a wasteful number, since it uses less digits than its factorization.

161291951481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270170975.

The product of its digits is 155520, while the sum is 48.

It can be divided in two parts, 1612919 and 51481, that added together give a triangular number (1664400 = T₁₈₂₄).

The spelling of 161291951481 in words is "one hundred sixty-one billion, two hundred ninety-one million, nine hundred fifty-one thousand, four hundred eighty-one".