161223511 has 2 divisors, whose sum is σ = 161223512. Its totient is φ = 161223510.

The previous prime is 161223481. The next prime is 161223523. The reversal of 161223511 is 115322161.

It is a happy number.

161223511 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161223511 - 2⁵ = 161223479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161223551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80611755 + 80611756.

It is an arithmetic number, because the mean of its divisors is an integer number (80611756).

Almost surely, 2^161223511 is an apocalyptic number.

161223511 is a deficient number, since it is larger than the sum of its proper divisors (1).

161223511 is an equidigital number, since it uses as much as digits as its factorization.

161223511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 22.

The square root of 161223511 is about 12697.3820530060. The cubic root of 161223511 is about 544.2638108698.

Adding to 161223511 its reverse (115322161), we get a palindrome (276545672).

The spelling of 161223511 in words is "one hundred sixty-one million, two hundred twenty-three thousand, five hundred eleven".