18156461 has 2 divisors, whose sum is σ = 18156462. Its totient is φ = 18156460.

The previous prime is 18156433. The next prime is 18156503. The reversal of 18156461 is 16465181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16933225 + 1223236 = 4115^2 + 1106^2 .

It is a cyclic number.

It is not a de Polignac number, because 18156461 - 2¹⁰ = 18155437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18156401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9078230 + 9078231.

It is an arithmetic number, because the mean of its divisors is an integer number (9078231).

Almost surely, 2^18156461 is an apocalyptic number.

It is an amenable number.

18156461 is a deficient number, since it is larger than the sum of its proper divisors (1).

18156461 is an equidigital number, since it uses as much as digits as its factorization.

18156461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 32.

The square root of 18156461 is about 4261.0398965511. The cubic root of 18156461 is about 262.8312902577.

The spelling of 18156461 in words is "eighteen million, one hundred fifty-six thousand, four hundred sixty-one".