1982891909 has 2 divisors, whose sum is σ = 1982891910. Its totient is φ = 1982891908.

The previous prime is 1982891899. The next prime is 1982891947. The reversal of 1982891909 is 9091982891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1902878884 + 80013025 = 43622^2 + 8945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1982891909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1982891959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 991445954 + 991445955.

It is an arithmetic number, because the mean of its divisors is an integer number (991445955).

Almost surely, 2^1982891909 is an apocalyptic number.

It is an amenable number.

1982891909 is a deficient number, since it is larger than the sum of its proper divisors (1).

1982891909 is an equidigital number, since it uses as much as digits as its factorization.

1982891909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 839808, while the sum is 56.

The square root of 1982891909 is about 44529.6744766903. The cubic root of 1982891909 is about 1256.3182835453.

The spelling of 1982891909 in words is "one billion, nine hundred eighty-two million, eight hundred ninety-one thousand, nine hundred nine".