18144440 has 32 divisors (see below), whose sum is σ = 43228080. Its totient is φ = 6830592.

The previous prime is 18144437. The next prime is 18144443. The reversal of 18144440 is 4444181.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18144437) and next prime (18144443).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18144443) 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, 12662 + ... + 14021.

Almost surely, 2^18144440 is an apocalyptic number.

18144440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18144440 is an abundant number, since it is smaller than the sum of its proper divisors (25083640).

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

18144440 is a wasteful number, since it uses less digits than its factorization.

18144440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26711 (or 26707 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 26.

The square root of 18144440 is about 4259.6290918342. The cubic root of 18144440 is about 262.7732724815.

The spelling of 18144440 in words is "eighteen million, one hundred forty-four thousand, four hundred forty".