161403251 has 2 divisors, whose sum is σ = 161403252. Its totient is φ = 161403250.

The previous prime is 161403239. The next prime is 161403257. The reversal of 161403251 is 152304161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161403251 - 2¹⁸ = 161141107 is a prime.

It is not a weakly prime, because it can be changed into another prime (161403257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80701625 + 80701626.

It is an arithmetic number, because the mean of its divisors is an integer number (80701626).

Almost surely, 2^161403251 is an apocalyptic number.

161403251 is a deficient number, since it is larger than the sum of its proper divisors (1).

161403251 is an equidigital number, since it uses as much as digits as its factorization.

161403251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 161403251 is about 12704.4579183844. The cubic root of 161403251 is about 544.4659932221.

It can be divided in two parts, 16140 and 3251, that added together give a palindrome (19391).

The spelling of 161403251 in words is "one hundred sixty-one million, four hundred three thousand, two hundred fifty-one".