161355261 has 8 divisors (see below), whose sum is σ = 220955104. Its totient is φ = 104662800.

The previous prime is 161355253. The next prime is 161355269. The reversal of 161355261 is 162553161.

It is an interprime number because it is at equal distance from previous prime (161355253) and next prime (161355269).

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

It is not a de Polignac number, because 161355261 - 2³ = 161355253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161355269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 726715 + ... + 726936.

It is an arithmetic number, because the mean of its divisors is an integer number (27619388).

Almost surely, 2^161355261 is an apocalyptic number.

It is an amenable number.

161355261 is a deficient number, since it is larger than the sum of its proper divisors (59599843).

161355261 is a wasteful number, since it uses less digits than its factorization.

161355261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1453691.

The product of its digits is 5400, while the sum is 30.

The square root of 161355261 is about 12702.5690708612. The cubic root of 161355261 is about 544.4120258806.

The spelling of 161355261 in words is "one hundred sixty-one million, three hundred fifty-five thousand, two hundred sixty-one".