161581223 has 2 divisors, whose sum is σ = 161581224. Its totient is φ = 161581222.

The previous prime is 161581177. The next prime is 161581237. The reversal of 161581223 is 322185161.

It is a strong prime.

It is an emirp because it is prime and its reverse (322185161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161581223 - 2¹² = 161577127 is a prime.

It is a super-2 number, since 2×161581223² = 52216983252351458, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161551223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80790611 + 80790612.

It is an arithmetic number, because the mean of its divisors is an integer number (80790612).

Almost surely, 2^161581223 is an apocalyptic number.

161581223 is a deficient number, since it is larger than the sum of its proper divisors (1).

161581223 is an equidigital number, since it uses as much as digits as its factorization.

161581223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 29.

The square root of 161581223 is about 12711.4603016333. The cubic root of 161581223 is about 544.6660389819. Note that the first 3 decimals are identical.

The spelling of 161581223 in words is "one hundred sixty-one million, five hundred eighty-one thousand, two hundred twenty-three".