19827971523 has 24 divisors (see below), whose sum is σ = 28744717872. Its totient is φ = 13170567168.

The previous prime is 19827971521. The next prime is 19827971543. The reversal of 19827971523 is 32517972891.

It is a happy number.

19827971523 is a `hidden beast` number, since 1 + 9 + 8 + 27 + 97 + 1 + 523 = 666.

It is not a de Polignac number, because 19827971523 - 2¹ = 19827971521 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19827971523.

It is not an unprimeable number, because it can be changed into a prime (19827971521) 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, 6997515 + ... + 7000347.

It is an arithmetic number, because the mean of its divisors is an integer number (1197696578).

Almost surely, 2^19827971523 is an apocalyptic number.

19827971523 is a deficient number, since it is larger than the sum of its proper divisors (8916746349).

19827971523 is a wasteful number, since it uses less digits than its factorization.

19827971523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5395 (or 5392 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 54.

It can be divided in two parts, 19827 and 971523, that multiplied together give a square (19262386521 = 138789²).

The spelling of 19827971523 in words is "nineteen billion, eight hundred twenty-seven million, nine hundred seventy-one thousand, five hundred twenty-three".