18490691 has 2 divisors, whose sum is σ = 18490692. Its totient is φ = 18490690.

The previous prime is 18490673. The next prime is 18490697. The reversal of 18490691 is 19609481.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18490691 - 2⁶ = 18490627 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (18490697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9245345 + 9245346.

It is an arithmetic number, because the mean of its divisors is an integer number (9245346).

Almost surely, 2^18490691 is an apocalyptic number.

18490691 is a deficient number, since it is larger than the sum of its proper divisors (1).

18490691 is an equidigital number, since it uses as much as digits as its factorization.

18490691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 18490691 is about 4300.0803480865. The cubic root of 18490691 is about 264.4342552639.

The spelling of 18490691 in words is "eighteen million, four hundred ninety thousand, six hundred ninety-one".