161153581 has 2 divisors, whose sum is σ = 161153582. Its totient is φ = 161153580.

The previous prime is 161153533. The next prime is 161153623. The reversal of 161153581 is 185351161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137475625 + 23677956 = 11725^2 + 4866^2 .

It is a cyclic number.

It is not a de Polignac number, because 161153581 - 2¹³ = 161145389 is a prime.

It is a super-2 number, since 2×161153581² = 51940953338247122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161151581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80576790 + 80576791.

It is an arithmetic number, because the mean of its divisors is an integer number (80576791).

Almost surely, 2^161153581 is an apocalyptic number.

It is an amenable number.

161153581 is a deficient number, since it is larger than the sum of its proper divisors (1).

161153581 is an equidigital number, since it uses as much as digits as its factorization.

161153581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 31.

The square root of 161153581 is about 12694.6280370872. The cubic root of 161153581 is about 544.1851087991.

The spelling of 161153581 in words is "one hundred sixty-one million, one hundred fifty-three thousand, five hundred eighty-one".