161613261 has 12 divisors (see below), whose sum is σ = 240972160. Its totient is φ = 104266440.

The previous prime is 161613251. The next prime is 161613281. The reversal of 161613261 is 162316161.

It is not a de Polignac number, because 161613261 - 2⁶ = 161613197 is a prime.

It is a super-2 number, since 2×161613261² = 52237692262108242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161613211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 289351 + ... + 289908.

Almost surely, 2^161613261 is an apocalyptic number.

It is an amenable number.

161613261 is a deficient number, since it is larger than the sum of its proper divisors (79358899).

161613261 is a wasteful number, since it uses less digits than its factorization.

161613261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579296 (or 579293 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 161613261 is about 12712.7204405666. The cubic root of 161613261 is about 544.7020350319.

The spelling of 161613261 in words is "one hundred sixty-one million, six hundred thirteen thousand, two hundred sixty-one".