79399861 has 2 divisors, whose sum is σ = 79399862. Its totient is φ = 79399860.

The previous prime is 79399829. The next prime is 79399871. The reversal of 79399861 is 16899397.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75359761 + 4040100 = 8681^2 + 2010^2 .

It is an emirp because it is prime and its reverse (16899397) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79399861 - 2⁵ = 79399829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 79399799 and 79399808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79399871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39699930 + 39699931.

It is an arithmetic number, because the mean of its divisors is an integer number (39699931).

Almost surely, 2^79399861 is an apocalyptic number.

It is an amenable number.

79399861 is a deficient number, since it is larger than the sum of its proper divisors (1).

79399861 is an equidigital number, since it uses as much as digits as its factorization.

79399861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 52.

The square root of 79399861 is about 8910.6599643349. The cubic root of 79399861 is about 429.8067655294.

The spelling of 79399861 in words is "seventy-nine million, three hundred ninety-nine thousand, eight hundred sixty-one".