79821943 has 2 divisors, whose sum is σ = 79821944. Its totient is φ = 79821942.

The previous prime is 79821901. The next prime is 79821961. The reversal of 79821943 is 34912897.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 79821943 - 2¹³ = 79813751 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 79821943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79821143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39910971 + 39910972.

It is an arithmetic number, because the mean of its divisors is an integer number (39910972).

Almost surely, 2^79821943 is an apocalyptic number.

79821943 is a deficient number, since it is larger than the sum of its proper divisors (1).

79821943 is an equidigital number, since it uses as much as digits as its factorization.

79821943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 43.

The square root of 79821943 is about 8934.3126764178. The cubic root of 79821943 is about 430.5670237284.

The spelling of 79821943 in words is "seventy-nine million, eight hundred twenty-one thousand, nine hundred forty-three".