83720993 has 2 divisors, whose sum is σ = 83720994. Its totient is φ = 83720992.

The previous prime is 83720977. The next prime is 83721013. The reversal of 83720993 is 39902738.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53173264 + 30547729 = 7292^2 + 5527^2 .

It is a cyclic number.

It is not a de Polignac number, because 83720993 - 2⁴ = 83720977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 83720993.

It is not a weakly prime, because it can be changed into another prime (83720933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41860496 + 41860497.

It is an arithmetic number, because the mean of its divisors is an integer number (41860497).

Almost surely, 2^83720993 is an apocalyptic number.

It is an amenable number.

83720993 is a deficient number, since it is larger than the sum of its proper divisors (1).

83720993 is an equidigital number, since it uses as much as digits as its factorization.

83720993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 83720993 is about 9149.9176499026. The cubic root of 83720993 is about 437.4664886441.

The spelling of 83720993 in words is "eighty-three million, seven hundred twenty thousand, nine hundred ninety-three".