18764865 has 40 divisors (see below), whose sum is σ = 38448960. Its totient is φ = 8576928.

The previous prime is 18764843. The next prime is 18764887. The reversal of 18764865 is 56846781.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18764843) and next prime (18764887).

It is not a de Polignac number, because 18764865 - 2⁹ = 18764353 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 18764865.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 475 + ... + 6144.

It is an arithmetic number, because the mean of its divisors is an integer number (961224).

Almost surely, 2^18764865 is an apocalyptic number.

18764865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18764865 is an abundant number, since it is smaller than the sum of its proper divisors (19684095).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18764865 is an equidigital number, since it uses as much as digits as its factorization.

18764865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6643 (or 6634 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 18764865 is about 4331.8431412044. The cubic root of 18764865 is about 265.7348300601.

The spelling of 18764865 in words is "eighteen million, seven hundred sixty-four thousand, eight hundred sixty-five".