18722840 has 16 divisors (see below), whose sum is σ = 42126480. Its totient is φ = 7489120.

The previous prime is 18722839. The next prime is 18722861. The reversal of 18722840 is 4822781.

It is a junction number, because it is equal to n+sod(n) for n = 18722797 and 18722806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233996 + ... + 234075.

It is an arithmetic number, because the mean of its divisors is an integer number (2632905).

Almost surely, 2^18722840 is an apocalyptic number.

18722840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18722840 is an abundant number, since it is smaller than the sum of its proper divisors (23403640).

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

18722840 is a wasteful number, since it uses less digits than its factorization.

18722840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468082 (or 468078 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 18722840 is about 4326.9897157262. The cubic root of 18722840 is about 265.5363056124.

The spelling of 18722840 in words is "eighteen million, seven hundred twenty-two thousand, eight hundred forty".