161315551 has 8 divisors (see below), whose sum is σ = 163635200. Its totient is φ = 159003000.

The previous prime is 161315543. The next prime is 161315579. The reversal of 161315551 is 155513161.

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

It is a cyclic number.

It is not a de Polignac number, because 161315551 - 2³ = 161315543 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 (161315591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57970 + ... + 60688.

It is an arithmetic number, because the mean of its divisors is an integer number (20454400).

Almost surely, 2^161315551 is an apocalyptic number.

161315551 is a deficient number, since it is larger than the sum of its proper divisors (2319649).

161315551 is an equidigital number, since it uses as much as digits as its factorization.

161315551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3549.

The product of its digits is 2250, while the sum is 28.

The square root of 161315551 is about 12701.0059050455. The cubic root of 161315551 is about 544.3673617544.

The spelling of 161315551 in words is "one hundred sixty-one million, three hundred fifteen thousand, five hundred fifty-one".