61939979 has 2 divisors, whose sum is σ = 61939980. Its totient is φ = 61939978.

The previous prime is 61939973. The next prime is 61939991. The reversal of 61939979 is 97993916.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61939979 - 2²⁰ = 60891403 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61939979.

It is not a weakly prime, because it can be changed into another prime (61939973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30969989 + 30969990.

It is an arithmetic number, because the mean of its divisors is an integer number (30969990).

Almost surely, 2^61939979 is an apocalyptic number.

61939979 is a deficient number, since it is larger than the sum of its proper divisors (1).

61939979 is an equidigital number, since it uses as much as digits as its factorization.

61939979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 826686, while the sum is 53.

The square root of 61939979 is about 7870.1956138332. The cubic root of 61939979 is about 395.6614011231.

The spelling of 61939979 in words is "sixty-one million, nine hundred thirty-nine thousand, nine hundred seventy-nine".