1981762499 has 2 divisors, whose sum is σ = 1981762500. Its totient is φ = 1981762498.

The previous prime is 1981762493. The next prime is 1981762553. The reversal of 1981762499 is 9942671891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1981762499 - 2⁸ = 1981762243 is a prime.

It is not a weakly prime, because it can be changed into another prime (1981762493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990881249 + 990881250.

It is an arithmetic number, because the mean of its divisors is an integer number (990881250).

Almost surely, 2^1981762499 is an apocalyptic number.

1981762499 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981762499 is an equidigital number, since it uses as much as digits as its factorization.

1981762499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 56.

The square root of 1981762499 is about 44516.9911269843. The cubic root of 1981762499 is about 1256.0797148329.

The spelling of 1981762499 in words is "one billion, nine hundred eighty-one million, seven hundred sixty-two thousand, four hundred ninety-nine".