19995115140 has 768 divisors, whose sum is σ = 84861665280. Its totient is φ = 3773952000.

The previous prime is 19995115123. The next prime is 19995115213. The reversal of 19995115140 is 4151159991.

It is a happy number.

19995115140 is a `hidden beast` number, since 1 + 9 + 99 + 511 + 5 + 1 + 40 = 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 255 ways as a sum of consecutive naturals, for example, 38378080 + ... + 38378600.

It is an arithmetic number, because the mean of its divisors is an integer number (110496960).

Almost surely, 2^19995115140 is an apocalyptic number.

19995115140 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 19995115140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42430832640).

19995115140 is an abundant number, since it is smaller than the sum of its proper divisors (64866550140).

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

19995115140 is a wasteful number, since it uses less digits than its factorization.

19995115140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 633 counting only the distinct ones).

The product of its (nonzero) digits is 72900, while the sum is 45.

The spelling of 19995115140 in words is "nineteen billion, nine hundred ninety-five million, one hundred fifteen thousand, one hundred forty".