18899951616 has 560 divisors, whose sum is σ = 69715038624. Its totient is φ = 4968677376.

The previous prime is 18899951597. The next prime is 18899951639. The reversal of 18899951616 is 61615999881.

18899951616 is a `hidden beast` number, since 1 + 8 + 8 + 9 + 9 + 9 + 5 + 1 + 616 = 666.

It is a super-2 number, since 2×18899951616² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 60383076 + ... + 60383388.

Almost surely, 2^18899951616 is an apocalyptic number.

18899951616 is a gapful number since it is divisible by the number (16) 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 18899951616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34857519312).

18899951616 is an abundant number, since it is smaller than the sum of its proper divisors (50815087008).

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

18899951616 is an equidigital number, since it uses as much as digits as its factorization.

18899951616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371 (or 338 counting only the distinct ones).

The product of its digits is 8398080, while the sum is 63.

The spelling of 18899951616 in words is "eighteen billion, eight hundred ninety-nine million, nine hundred fifty-one thousand, six hundred sixteen".