161611299251 has 2 divisors, whose sum is σ = 161611299252. Its totient is φ = 161611299250.

The previous prime is 161611299193. The next prime is 161611299263. The reversal of 161611299251 is 152992116161.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161611299251 is a prime.

It is a super-2 number, since 2×161611299251² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161611229251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80805649625 + 80805649626.

It is an arithmetic number, because the mean of its divisors is an integer number (80805649626).

Almost surely, 2^161611299251 is an apocalyptic number.

161611299251 is a deficient number, since it is larger than the sum of its proper divisors (1).

161611299251 is an equidigital number, since it uses as much as digits as its factorization.

161611299251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 44.

The spelling of 161611299251 in words is "one hundred sixty-one billion, six hundred eleven million, two hundred ninety-nine thousand, two hundred fifty-one".