61859777869 has 2 divisors, whose sum is σ = 61859777870. Its totient is φ = 61859777868.

The previous prime is 61859777827. The next prime is 61859777879. The reversal of 61859777869 is 96877795816.

61859777869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61783564969 + 76212900 = 248563^2 + 8730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61859777869 is a prime.

It is a super-2 number, since 2×61859777869² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61859777879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30929888934 + 30929888935.

It is an arithmetic number, because the mean of its divisors is an integer number (30929888935).

Almost surely, 2^61859777869 is an apocalyptic number.

It is an amenable number.

61859777869 is a deficient number, since it is larger than the sum of its proper divisors (1).

61859777869 is an equidigital number, since it uses as much as digits as its factorization.

61859777869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 320060160, while the sum is 73.

The spelling of 61859777869 in words is "sixty-one billion, eight hundred fifty-nine million, seven hundred seventy-seven thousand, eight hundred sixty-nine".