18234640 has 40 divisors (see below), whose sum is σ = 42651288. Its totient is φ = 7249920.

The previous prime is 18234631. The next prime is 18234691. The reversal of 18234640 is 4643281.

It can be written as a sum of positive squares in 4 ways, for example, as 3211264 + 15023376 = 1792^2 + 3876^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 18234599 and 18234608.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14850 + ... + 16030.

Almost surely, 2^18234640 is an apocalyptic number.

18234640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18234640 is an abundant number, since it is smaller than the sum of its proper divisors (24416648).

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

18234640 is a wasteful number, since it uses less digits than its factorization.

18234640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387 (or 1381 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 18234640 is about 4270.2037422118. The cubic root of 18234640 is about 263.2079874887.

The spelling of 18234640 in words is "eighteen million, two hundred thirty-four thousand, six hundred forty".