161253517698 has 96 divisors (see below), whose sum is σ = 431645550336. Its totient is φ = 42366582144.

The previous prime is 161253517657. The next prime is 161253517721. The reversal of 161253517698 is 896715352161.

161253517698 is a `hidden beast` number, since 1 + 6 + 1 + 2 + 535 + 17 + 6 + 98 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 243636 + ... + 617952.

It is an arithmetic number, because the mean of its divisors is an integer number (4496307816).

Almost surely, 2^161253517698 is an apocalyptic number.

161253517698 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 161253517698, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215822775168).

161253517698 is an abundant number, since it is smaller than the sum of its proper divisors (270392032638).

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

161253517698 is a wasteful number, since it uses less digits than its factorization.

161253517698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374608 (or 374605 counting only the distinct ones).

The product of its digits is 2721600, while the sum is 54.

The spelling of 161253517698 in words is "one hundred sixty-one billion, two hundred fifty-three million, five hundred seventeen thousand, six hundred ninety-eight".