161658551 has 8 divisors (see below), whose sum is σ = 165632544. Its totient is φ = 157731840.

The previous prime is 161658547. The next prime is 161658571. The reversal of 161658551 is 155856161.

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 161658551 - 2² = 161658547 is a prime.

It is a super-2 number, since 2×161658551² = 52266974222839202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161658571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4850 + ... + 18623.

It is an arithmetic number, because the mean of its divisors is an integer number (20704068).

Almost surely, 2^161658551 is an apocalyptic number.

161658551 is a deficient number, since it is larger than the sum of its proper divisors (3973993).

161658551 is an equidigital number, since it uses as much as digits as its factorization.

161658551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23641.

The product of its digits is 36000, while the sum is 38.

The square root of 161658551 is about 12714.5016025010. The cubic root of 161658551 is about 544.7529121504.

The spelling of 161658551 in words is "one hundred sixty-one million, six hundred fifty-eight thousand, five hundred fifty-one".