18946437840 has 480 divisors, whose sum is σ = 73773528192. Its totient is φ = 4478976000.

The previous prime is 18946437823. The next prime is 18946437857. The reversal of 18946437840 is 4873464981.

It is an interprime number because it is at equal distance from previous prime (18946437823) and next prime (18946437857).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8766360 + ... + 8768520.

Almost surely, 2^18946437840 is an apocalyptic number.

18946437840 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 18946437840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36886764096).

18946437840 is an abundant number, since it is smaller than the sum of its proper divisors (54827090352).

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

18946437840 is a wasteful number, since it uses less digits than its factorization.

18946437840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2241 (or 2223 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 54.

The spelling of 18946437840 in words is "eighteen billion, nine hundred forty-six million, four hundred thirty-seven thousand, eight hundred forty".