161605351 has 4 divisors (see below), whose sum is σ = 161704192. Its totient is φ = 161506512.

The previous prime is 161605333. The next prime is 161605357. The reversal of 161605351 is 153506161.

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

It is a cyclic number.

It is not a de Polignac number, because 161605351 - 2⁵ = 161605319 is a prime.

It is a super-2 number, since 2×161605351² = 52232578943666402, 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 (161605357) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46926 + ... + 50251.

It is an arithmetic number, because the mean of its divisors is an integer number (40426048).

Almost surely, 2^161605351 is an apocalyptic number.

161605351 is a deficient number, since it is larger than the sum of its proper divisors (98841).

161605351 is an equidigital number, since it uses as much as digits as its factorization.

161605351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98840.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 161605351 is about 12712.4093310434. The cubic root of 161605351 is about 544.6931482542.

The spelling of 161605351 in words is "one hundred sixty-one million, six hundred five thousand, three hundred fifty-one".