61789979 has 2 divisors, whose sum is σ = 61789980. Its totient is φ = 61789978.

The previous prime is 61789939. The next prime is 61789991. The reversal of 61789979 is 97998716.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61789979 - 2²⁰ = 60741403 is a prime.

It is not a weakly prime, because it can be changed into another prime (61789909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30894989 + 30894990.

It is an arithmetic number, because the mean of its divisors is an integer number (30894990).

Almost surely, 2^61789979 is an apocalyptic number.

61789979 is a deficient number, since it is larger than the sum of its proper divisors (1).

61789979 is an equidigital number, since it uses as much as digits as its factorization.

61789979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 56.

The square root of 61789979 is about 7860.6602140024. The cubic root of 61789979 is about 395.3417519814.

The spelling of 61789979 in words is "sixty-one million, seven hundred eighty-nine thousand, nine hundred seventy-nine".