19850399136 has 360 divisors, whose sum is σ = 63131612544. Its totient is φ = 6111832320.

The previous prime is 19850399123. The next prime is 19850399209. The reversal of 19850399136 is 63199305891.

19850399136 is a `hidden beast` number, since 19 + 8 + 503 + 9 + 91 + 36 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 42505975 + ... + 42506441.

Almost surely, 2^19850399136 is an apocalyptic number.

19850399136 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 19850399136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31565806272).

19850399136 is an abundant number, since it is smaller than the sum of its proper divisors (43281213408).

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

19850399136 is a wasteful number, since it uses less digits than its factorization.

19850399136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566 (or 526 counting only the distinct ones).

The product of its (nonzero) digits is 1574640, while the sum is 54.

The spelling of 19850399136 in words is "nineteen billion, eight hundred fifty million, three hundred ninety-nine thousand, one hundred thirty-six".