19815916140 has 72 divisors (see below), whose sum is σ = 62334526800. Its totient is φ = 5284243008.

The previous prime is 19815916129. The next prime is 19815916163. The reversal of 19815916140 is 4161951891.

19815916140 is a `hidden beast` number, since 19 + 8 + 1 + 591 + 6 + 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 23 ways as a sum of consecutive naturals, for example, 2033815 + ... + 2043534.

Almost surely, 2^19815916140 is an apocalyptic number.

19815916140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19815916140 is an abundant number, since it is smaller than the sum of its proper divisors (42518610660).

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

19815916140 is a wasteful number, since it uses less digits than its factorization.

19815916140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4077373 (or 4077359 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 45.

The spelling of 19815916140 in words is "nineteen billion, eight hundred fifteen million, nine hundred sixteen thousand, one hundred forty".