123161391345440 has 72 divisors (see below), whose sum is σ = 338473895165532. Its totient is φ = 42226762744320.

The previous prime is 123161391345407. The next prime is 123161391345479. The reversal of 123161391345440 is 44543193161321.

It can be written as a sum of positive squares in 2 ways, for example, as 113515472244496 + 9645919100944 = 10654364^2 + 3105788^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7854672731 + ... + 7854688410.

Almost surely, 2^{123161391345440} is an apocalyptic number.

123161391345440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123161391345440 is an abundant number, since it is smaller than the sum of its proper divisors (215312503820092).

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

123161391345440 is a wasteful number, since it uses less digits than its factorization.

123161391345440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15709361170 (or 15709361155 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 123161391345440 in words is "one hundred twenty-three trillion, one hundred sixty-one billion, three hundred ninety-one million, three hundred forty-five thousand, four hundred forty".