79803991 has 2 divisors, whose sum is σ = 79803992. Its totient is φ = 79803990.

The previous prime is 79803989. The next prime is 79804003. The reversal of 79803991 is 19930897.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 79803991 - 2¹ = 79803989 is a prime.

Together with 79803989, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79803091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39901995 + 39901996.

It is an arithmetic number, because the mean of its divisors is an integer number (39901996).

Almost surely, 2^79803991 is an apocalyptic number.

79803991 is a deficient number, since it is larger than the sum of its proper divisors (1).

79803991 is an equidigital number, since it uses as much as digits as its factorization.

79803991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 79803991 is about 8933.3079539440. The cubic root of 79803991 is about 430.5347430529.

The spelling of 79803991 in words is "seventy-nine million, eight hundred three thousand, nine hundred ninety-one".