18490817 has 4 divisors (see below), whose sum is σ = 18920880. Its totient is φ = 18060756.

The previous prime is 18490807. The next prime is 18490841. The reversal of 18490817 is 71809481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71809481 = 29 ⋅2476189.

It is a cyclic number.

It is not a de Polignac number, because 18490817 - 2²⁴ = 1713601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18490807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 214967 + ... + 215052.

It is an arithmetic number, because the mean of its divisors is an integer number (4730220).

Almost surely, 2^18490817 is an apocalyptic number.

It is an amenable number.

18490817 is a deficient number, since it is larger than the sum of its proper divisors (430063).

18490817 is an equidigital number, since it uses as much as digits as its factorization.

18490817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430062.

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 18490817 is about 4300.0949989506. The cubic root of 18490817 is about 264.4348559020.

It can be divided in two parts, 18 and 490817, that multiplied together give a triangular number (8834706 = T₄₂₀₃).

The spelling of 18490817 in words is "eighteen million, four hundred ninety thousand, eight hundred seventeen".