18651161 has 2 divisors, whose sum is σ = 18651162. Its totient is φ = 18651160.

The previous prime is 18651133. The next prime is 18651167. The reversal of 18651161 is 16115681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11055625 + 7595536 = 3325^2 + 2756^2 .

It is a cyclic number.

It is not a de Polignac number, because 18651161 - 2⁶ = 18651097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18651167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9325580 + 9325581.

It is an arithmetic number, because the mean of its divisors is an integer number (9325581).

Almost surely, 2^18651161 is an apocalyptic number.

It is an amenable number.

18651161 is a deficient number, since it is larger than the sum of its proper divisors (1).

18651161 is an equidigital number, since it uses as much as digits as its factorization.

18651161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 29.

The square root of 18651161 is about 4318.6989939101. The cubic root of 18651161 is about 265.1970102574.

The spelling of 18651161 in words is "eighteen million, six hundred fifty-one thousand, one hundred sixty-one".