79690421 has 2 divisors, whose sum is σ = 79690422. Its totient is φ = 79690420.

The previous prime is 79690411. The next prime is 79690451. The reversal of 79690421 is 12409697.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78127921 + 1562500 = 8839^2 + 1250^2 .

It is an emirp because it is prime and its reverse (12409697) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79690421 - 2¹⁴ = 79674037 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79690411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39845210 + 39845211.

It is an arithmetic number, because the mean of its divisors is an integer number (39845211).

Almost surely, 2^79690421 is an apocalyptic number.

It is an amenable number.

79690421 is a deficient number, since it is larger than the sum of its proper divisors (1).

79690421 is an equidigital number, since it uses as much as digits as its factorization.

79690421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 79690421 is about 8926.9491429043. The cubic root of 79690421 is about 430.3304130720.

The spelling of 79690421 in words is "seventy-nine million, six hundred ninety thousand, four hundred twenty-one".