18909740 has 24 divisors (see below), whose sum is σ = 41081040. Its totient is φ = 7302848.

The previous prime is 18909727. The next prime is 18909743. The reversal of 18909740 is 4790981.

It is a junction number, because it is equal to n+sod(n) for n = 18909694 and 18909703.

It is not an unprimeable number, because it can be changed into a prime (18909743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15722 + ... + 16881.

It is an arithmetic number, because the mean of its divisors is an integer number (1711710).

Almost surely, 2^18909740 is an apocalyptic number.

18909740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18909740 is an abundant number, since it is smaller than the sum of its proper divisors (22171300).

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

18909740 is a wasteful number, since it uses less digits than its factorization.

18909740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32641 (or 32639 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 18909740 is about 4348.5330859958. The cubic root of 18909740 is about 266.4169502572.

The spelling of 18909740 in words is "eighteen million, nine hundred nine thousand, seven hundred forty".