18909495 has 24 divisors (see below), whose sum is σ = 35757072. Its totient is φ = 9168000.

The previous prime is 18909493. The next prime is 18909497. The reversal of 18909495 is 59490981.

It is an interprime number because it is at equal distance from previous prime (18909493) and next prime (18909497).

It is not a de Polignac number, because 18909495 - 2¹ = 18909493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 18909495.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18909493) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18606 + ... + 19595.

It is an arithmetic number, because the mean of its divisors is an integer number (1489878).

Almost surely, 2^18909495 is an apocalyptic number.

18909495 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18909495 is a deficient number, since it is larger than the sum of its proper divisors (16847577).

18909495 is a wasteful number, since it uses less digits than its factorization.

18909495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38223 (or 38220 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 18909495 is about 4348.5049154853. The cubic root of 18909495 is about 266.4157996608.

The spelling of 18909495 in words is "eighteen million, nine hundred nine thousand, four hundred ninety-five".