18991925064 has 512 divisors, whose sum is σ = 65558937600. Its totient is φ = 4979128320.

The previous prime is 18991925063. The next prime is 18991925093. The reversal of 18991925064 is 46052919981.

It is a super-3 number, since 3×18991925064³ (a number of 32 digits) contains 333 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18991925064.

It is not an unprimeable number, because it can be changed into a prime (18991925063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 81510292 + ... + 81510524.

It is an arithmetic number, because the mean of its divisors is an integer number (128044800).

Almost surely, 2^18991925064 is an apocalyptic number.

18991925064 is a gapful number since it is divisible by the number (14) 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 18991925064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32779468800).

18991925064 is an abundant number, since it is smaller than the sum of its proper divisors (46567012536).

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

18991925064 is a wasteful number, since it uses less digits than its factorization.

18991925064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 18991925064 in words is "eighteen billion, nine hundred ninety-one million, nine hundred twenty-five thousand, sixty-four".