161226811 has 2 divisors, whose sum is σ = 161226812. Its totient is φ = 161226810.

The previous prime is 161226787. The next prime is 161226817. The reversal of 161226811 is 118622161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161226811 - 2⁷ = 161226683 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161226811.

It is not a weakly prime, because it can be changed into another prime (161226817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80613405 + 80613406.

It is an arithmetic number, because the mean of its divisors is an integer number (80613406).

Almost surely, 2^161226811 is an apocalyptic number.

161226811 is the 5679-th centered decagonal number.

161226811 is a deficient number, since it is larger than the sum of its proper divisors (1).

161226811 is an equidigital number, since it uses as much as digits as its factorization.

161226811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 28.

The square root of 161226811 is about 12697.5120003881. The cubic root of 161226811 is about 544.2675242619.

Adding to 161226811 its reverse (118622161), we get a palindrome (279848972).

The spelling of 161226811 in words is "one hundred sixty-one million, two hundred twenty-six thousand, eight hundred eleven".