18491040 has 72 divisors (see below), whose sum is σ = 63105588. Its totient is φ = 4930560.

The previous prime is 18491029. The next prime is 18491051. The reversal of 18491040 is 4019481.

It is an interprime number because it is at equal distance from previous prime (18491029) and next prime (18491051).

It can be written as a sum of positive squares in 2 ways, for example, as 18352656 + 138384 = 4284^2 + 372^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a junction number, because it is equal to n+sod(n) for n = 18490995 and 18491013.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4981 + ... + 7860.

Almost surely, 2^18491040 is an apocalyptic number.

18491040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18491040 is an abundant number, since it is smaller than the sum of its proper divisors (44614548).

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

18491040 is a wasteful number, since it uses less digits than its factorization.

18491040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12862 (or 12851 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 18491040 is about 4300.1209285321. The cubic root of 18491040 is about 264.4359189294.

The spelling of 18491040 in words is "eighteen million, four hundred ninety-one thousand, forty".