18491944140 has 192 divisors, whose sum is σ = 62212147200. Its totient is φ = 4542262272.

The previous prime is 18491944139. The next prime is 18491944193. The reversal of 18491944140 is 4144919481.

It is a happy number.

18491944140 is a `hidden beast` number, since 1 + 8 + 49 + 194 + 414 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 410031 + ... + 452889.

It is an arithmetic number, because the mean of its divisors is an integer number (324021600).

Almost surely, 2^18491944140 is an apocalyptic number.

18491944140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18491944140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31106073600).

18491944140 is an abundant number, since it is smaller than the sum of its proper divisors (43720203060).

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

18491944140 is a wasteful number, since it uses less digits than its factorization.

18491944140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42941 (or 42933 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

It can be divided in two parts, 184919441 and 40, that added together give a palindrome (184919481).

The spelling of 18491944140 in words is "eighteen billion, four hundred ninety-one million, nine hundred forty-four thousand, one hundred forty".