61859909 has 2 divisors, whose sum is σ = 61859910. Its totient is φ = 61859908.

The previous prime is 61859899. The next prime is 61859921. The reversal of 61859909 is 90995816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51523684 + 10336225 = 7178^2 + 3215^2 .

It is a cyclic number.

It is not a de Polignac number, because 61859909 - 2¹² = 61855813 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61852909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30929954 + 30929955.

It is an arithmetic number, because the mean of its divisors is an integer number (30929955).

Almost surely, 2^61859909 is an apocalyptic number.

It is an amenable number.

61859909 is a deficient number, since it is larger than the sum of its proper divisors (1).

61859909 is an equidigital number, since it uses as much as digits as its factorization.

61859909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 174960, while the sum is 47.

The square root of 61859909 is about 7865.1070558512. The cubic root of 61859909 is about 395.4908367051.

The spelling of 61859909 in words is "sixty-one million, eight hundred fifty-nine thousand, nine hundred nine".