18900949 has 2 divisors, whose sum is σ = 18900950. Its totient is φ = 18900948.

The previous prime is 18900943. The next prime is 18900961. The reversal of 18900949 is 94900981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10595025 + 8305924 = 3255^2 + 2882^2 .

It is a cyclic number.

It is not a de Polignac number, because 18900949 - 2⁹ = 18900437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18900943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9450474 + 9450475.

It is an arithmetic number, because the mean of its divisors is an integer number (9450475).

Almost surely, 2^18900949 is an apocalyptic number.

It is an amenable number.

18900949 is a deficient number, since it is larger than the sum of its proper divisors (1).

18900949 is an equidigital number, since it uses as much as digits as its factorization.

18900949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 18900949 is about 4347.5221678561. The cubic root of 18900949 is about 266.3756587598.

The spelling of 18900949 in words is "eighteen million, nine hundred thousand, nine hundred forty-nine".