1971231538 has 12 divisors (see below), whose sum is σ = 3029583438. Its totient is φ = 961380240.

The previous prime is 1971231523. The next prime is 1971231599. The reversal of 1971231538 is 8351321791.

It can be written as a sum of positive squares in only one way, i.e., 1947192129 + 24039409 = 44127^2 + 4903^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1971231538.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 399595 + ... + 404497.

Almost surely, 2^1971231538 is an apocalyptic number.

1971231538 is a deficient number, since it is larger than the sum of its proper divisors (1058351900).

1971231538 is an frugal number, since it uses more digits than its factorization.

1971231538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9849 (or 4946 counting only the distinct ones).

The product of its digits is 45360, while the sum is 40.

The square root of 1971231538 is about 44398.5533322878. The cubic root of 1971231538 is about 1253.8508526713.

The spelling of 1971231538 in words is "one billion, nine hundred seventy-one million, two hundred thirty-one thousand, five hundred thirty-eight".