1971019823 has 2 divisors, whose sum is σ = 1971019824. Its totient is φ = 1971019822.

The previous prime is 1971019819. The next prime is 1971019847. The reversal of 1971019823 is 3289101791.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1971019823 - 2² = 1971019819 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1971019873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985509911 + 985509912.

It is an arithmetic number, because the mean of its divisors is an integer number (985509912).

Almost surely, 2^1971019823 is an apocalyptic number.

1971019823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971019823 is an equidigital number, since it uses as much as digits as its factorization.

1971019823 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 1971019823 is about 44396.1690126524. The cubic root of 1971019823 is about 1253.8059622002.

The spelling of 1971019823 in words is "one billion, nine hundred seventy-one million, nineteen thousand, eight hundred twenty-three".