19871193780 has 72 divisors (see below), whose sum is σ = 62508412512. Its totient is φ = 5298983712.

The previous prime is 19871193773. The next prime is 19871193787. The reversal of 19871193780 is 8739117891.

19871193780 is a `hidden beast` number, since 198 + 71 + 19 + 378 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (19871193773) and next prime (19871193787).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19871193787) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2039502 + ... + 2049221.

It is an arithmetic number, because the mean of its divisors is an integer number (868172396).

Almost surely, 2^19871193780 is an apocalyptic number.

19871193780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19871193780 is an abundant number, since it is smaller than the sum of its proper divisors (42637218732).

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

19871193780 is a wasteful number, since it uses less digits than its factorization.

19871193780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4088747 (or 4088733 counting only the distinct ones).

The product of its (nonzero) digits is 762048, while the sum is 54.

The spelling of 19871193780 in words is "nineteen billion, eight hundred seventy-one million, one hundred ninety-three thousand, seven hundred eighty".