19851983 has 2 divisors, whose sum is σ = 19851984. Its totient is φ = 19851982.

The previous prime is 19851977. The next prime is 19851991. The reversal of 19851983 is 38915891.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19851983 - 2⁶ = 19851919 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19851973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9925991 + 9925992.

It is an arithmetic number, because the mean of its divisors is an integer number (9925992).

Almost surely, 2^19851983 is an apocalyptic number.

19851983 is a deficient number, since it is larger than the sum of its proper divisors (1).

19851983 is an equidigital number, since it uses as much as digits as its factorization.

19851983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 44.

The square root of 19851983 is about 4455.5564186754. The cubic root of 19851983 is about 270.7704696280.

The spelling of 19851983 in words is "nineteen million, eight hundred fifty-one thousand, nine hundred eighty-three".