18961916400 has 960 divisors, whose sum is σ = 83350220800. Its totient is φ = 3997486080.

The previous prime is 18961916387. The next prime is 18961916417. The reversal of 18961916400 is 461916981.

18961916400 is a `hidden beast` number, since 18 + 9 + 619 + 16 + 4 + 0 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 61765047 + ... + 61765353.

Almost surely, 2^18961916400 is an apocalyptic number.

18961916400 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 18961916400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41675110400).

18961916400 is an abundant number, since it is smaller than the sum of its proper divisors (64388304400).

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

18961916400 is a wasteful number, since it uses less digits than its factorization.

18961916400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 18961916400 in words is "eighteen billion, nine hundred sixty-one million, nine hundred sixteen thousand, four hundred".