1971138835 has 4 divisors (see below), whose sum is σ = 2365366608. Its totient is φ = 1576911064.

The previous prime is 1971138823. The next prime is 1971138839. The reversal of 1971138835 is 5388311791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1971138835 - 2¹³ = 1971130643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971138839) 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 3 ways as a sum of consecutive naturals, for example, 197113879 + ... + 197113888.

It is an arithmetic number, because the mean of its divisors is an integer number (591341652).

Almost surely, 2^1971138835 is an apocalyptic number.

1971138835 is a deficient number, since it is larger than the sum of its proper divisors (394227773).

1971138835 is an equidigital number, since it uses as much as digits as its factorization.

1971138835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394227772.

The product of its digits is 181440, while the sum is 46.

The square root of 1971138835 is about 44397.5093332948. The cubic root of 1971138835 is about 1253.8311970135.

The spelling of 1971138835 in words is "one billion, nine hundred seventy-one million, one hundred thirty-eight thousand, eight hundred thirty-five".