18504961 has 2 divisors, whose sum is σ = 18504962. Its totient is φ = 18504960.

The previous prime is 18504953. The next prime is 18504973. The reversal of 18504961 is 16940581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10439361 + 8065600 = 3231^2 + 2840^2 .

It is a cyclic number.

It is not a de Polignac number, because 18504961 - 2³ = 18504953 is a prime.

It is a super-2 number, since 2×18504961² = 684867163223042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18504991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9252480 + 9252481.

It is an arithmetic number, because the mean of its divisors is an integer number (9252481).

Almost surely, 2^18504961 is an apocalyptic number.

It is an amenable number.

18504961 is a deficient number, since it is larger than the sum of its proper divisors (1).

18504961 is an equidigital number, since it uses as much as digits as its factorization.

18504961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 18504961 is about 4301.7392993997. The cubic root of 18504961 is about 264.5022625750.

The spelling of 18504961 in words is "eighteen million, five hundred four thousand, nine hundred sixty-one".