21492311161 has 2 divisors, whose sum is σ = 21492311162. Its totient is φ = 21492311160.

The previous prime is 21492311131. The next prime is 21492311173. The reversal of 21492311161 is 16111329412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14293637136 + 7198674025 = 119556^2 + 84845^2 .

It is a cyclic number.

It is not a de Polignac number, because 21492311161 - 2¹³ = 21492302969 is a prime.

It is not a weakly prime, because it can be changed into another prime (21492311131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10746155580 + 10746155581.

It is an arithmetic number, because the mean of its divisors is an integer number (10746155581).

Almost surely, 2^21492311161 is an apocalyptic number.

It is an amenable number.

21492311161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21492311161 is an equidigital number, since it uses as much as digits as its factorization.

21492311161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 31.

The spelling of 21492311161 in words is "twenty-one billion, four hundred ninety-two million, three hundred eleven thousand, one hundred sixty-one".