161520421211 has 2 divisors, whose sum is σ = 161520421212. Its totient is φ = 161520421210.

The previous prime is 161520421171. The next prime is 161520421291. The reversal of 161520421211 is 112124025161.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161520421211 is a prime.

It is not a weakly prime, because it can be changed into another prime (161520421291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80760210605 + 80760210606.

It is an arithmetic number, because the mean of its divisors is an integer number (80760210606).

Almost surely, 2^161520421211 is an apocalyptic number.

161520421211 is a deficient number, since it is larger than the sum of its proper divisors (1).

161520421211 is an equidigital number, since it uses as much as digits as its factorization.

161520421211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 26.

Adding to 161520421211 its reverse (112124025161), we get a palindrome (273644446372).

The spelling of 161520421211 in words is "one hundred sixty-one billion, five hundred twenty million, four hundred twenty-one thousand, two hundred eleven".