1971117819 has 48 divisors (see below), whose sum is σ = 3358817280. Its totient is φ = 1100378880.

The previous prime is 1971117793. The next prime is 1971117821. The reversal of 1971117819 is 9187111791.

It is a happy number.

It is not a de Polignac number, because 1971117819 - 2¹³ = 1971109627 is a prime.

It is a super-2 number, since 2×1971117819² = 7770610912758633522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1971117419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 66642 + ... + 91560.

It is an arithmetic number, because the mean of its divisors is an integer number (69975360).

Almost surely, 2^1971117819 is an apocalyptic number.

1971117819 is a deficient number, since it is larger than the sum of its proper divisors (1387699461).

1971117819 is a wasteful number, since it uses less digits than its factorization.

1971117819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25000 (or 24997 counting only the distinct ones).

The product of its digits is 31752, while the sum is 45.

The square root of 1971117819 is about 44397.2726527205. The cubic root of 1971117819 is about 1253.8267409414.

The spelling of 1971117819 in words is "one billion, nine hundred seventy-one million, one hundred seventeen thousand, eight hundred nineteen".