1981340783 has 2 divisors, whose sum is σ = 1981340784. Its totient is φ = 1981340782.

The previous prime is 1981340759. The next prime is 1981340821. The reversal of 1981340783 is 3870431891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1981340783 - 2²⁴ = 1964563567 is a prime.

It is a super-3 number, since 3×1981340783³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981348783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990670391 + 990670392.

It is an arithmetic number, because the mean of its divisors is an integer number (990670392).

Almost surely, 2^1981340783 is an apocalyptic number.

1981340783 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981340783 is an equidigital number, since it uses as much as digits as its factorization.

1981340783 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 1981340783 is about 44512.2543014842. The cubic root of 1981340783 is about 1255.9906112376.

The spelling of 1981340783 in words is "one billion, nine hundred eighty-one million, three hundred forty thousand, seven hundred eighty-three".