19878806520 has 96 divisors (see below), whose sum is σ = 68406502320. Its totient is φ = 4989189120.

The previous prime is 19878806501. The next prime is 19878806527. The reversal of 19878806520 is 2560887891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19878806527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1617966 + ... + 1630205.

Almost surely, 2^19878806520 is an apocalyptic number.

19878806520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19878806520 is an abundant number, since it is smaller than the sum of its proper divisors (48527695800).

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

19878806520 is a wasteful number, since it uses less digits than its factorization.

19878806520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3248205 (or 3248198 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 54.

The spelling of 19878806520 in words is "nineteen billion, eight hundred seventy-eight million, eight hundred six thousand, five hundred twenty".