61997935309 has 2 divisors, whose sum is σ = 61997935310. Its totient is φ = 61997935308.

The previous prime is 61997935267. The next prime is 61997935319. The reversal of 61997935309 is 90353979916.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60420098025 + 1577837284 = 245805^2 + 39722^2 .

It is a cyclic number.

It is not a de Polignac number, because 61997935309 - 2²³ = 61989546701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61997935319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30998967654 + 30998967655.

It is an arithmetic number, because the mean of its divisors is an integer number (30998967655).

Almost surely, 2^61997935309 is an apocalyptic number.

It is an amenable number.

61997935309 is a deficient number, since it is larger than the sum of its proper divisors (1).

61997935309 is an equidigital number, since it uses as much as digits as its factorization.

61997935309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12400290, while the sum is 61.

The spelling of 61997935309 in words is "sixty-one billion, nine hundred ninety-seven million, nine hundred thirty-five thousand, three hundred nine".