79069981 has 2 divisors, whose sum is σ = 79069982. Its totient is φ = 79069980.

The previous prime is 79069951. The next prime is 79069987. The reversal of 79069981 is 18996097.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75951225 + 3118756 = 8715^2 + 1766^2 .

It is an emirp because it is prime and its reverse (18996097) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79069981 - 2¹³ = 79061789 is a prime.

It is a super-2 number, since 2×79069981² = 12504123790680722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79069987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39534990 + 39534991.

It is an arithmetic number, because the mean of its divisors is an integer number (39534991).

Almost surely, 2^79069981 is an apocalyptic number.

It is an amenable number.

79069981 is a deficient number, since it is larger than the sum of its proper divisors (1).

79069981 is an equidigital number, since it uses as much as digits as its factorization.

79069981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 79069981 is about 8892.1302846956. The cubic root of 79069981 is about 429.2107045938.

The spelling of 79069981 in words is "seventy-nine million, sixty-nine thousand, nine hundred eighty-one".