19871156494 has 24 divisors (see below), whose sum is σ = 34766161848. Its totient is φ = 8493362640.

The previous prime is 19871156491. The next prime is 19871156563. The reversal of 19871156494 is 49465117891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19871156491) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235252 + ... + 308359.

It is an arithmetic number, because the mean of its divisors is an integer number (1448590077).

Almost surely, 2^19871156494 is an apocalyptic number.

19871156494 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

19871156494 is a deficient number, since it is larger than the sum of its proper divisors (14895005354).

19871156494 is a wasteful number, since it uses less digits than its factorization.

19871156494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544000 (or 543993 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 55.

The spelling of 19871156494 in words is "nineteen billion, eight hundred seventy-one million, one hundred fifty-six thousand, four hundred ninety-four".