161736251242 has 4 divisors (see below), whose sum is σ = 242604376866. Its totient is φ = 80868125620.

The previous prime is 161736251207. The next prime is 161736251251. The reversal of 161736251242 is 242152637161.

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

It can be written as a sum of positive squares in only one way, i.e., 112922209521 + 48814041721 = 336039^2 + 220939^2 .

It is a super-2 number, since 2×161736251242² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161736251195 and 161736251204.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40434062809 + ... + 40434062812.

Almost surely, 2^161736251242 is an apocalyptic number.

161736251242 is a deficient number, since it is larger than the sum of its proper divisors (80868125624).

161736251242 is an equidigital number, since it uses as much as digits as its factorization.

161736251242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80868125623.

The product of its digits is 120960, while the sum is 40.

The spelling of 161736251242 in words is "one hundred sixty-one billion, seven hundred thirty-six million, two hundred fifty-one thousand, two hundred forty-two".