61809906877 has 2 divisors, whose sum is σ = 61809906878. Its totient is φ = 61809906876.

The previous prime is 61809906857. The next prime is 61809906931. The reversal of 61809906877 is 77860990816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57802257241 + 4007649636 = 240421^2 + 63306^2 .

It is a cyclic number.

It is not a de Polignac number, because 61809906877 - 2¹¹ = 61809904829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61809906857) 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, 30904953438 + 30904953439.

It is an arithmetic number, because the mean of its divisors is an integer number (30904953439).

Almost surely, 2^61809906877 is an apocalyptic number.

It is an amenable number.

61809906877 is a deficient number, since it is larger than the sum of its proper divisors (1).

61809906877 is an equidigital number, since it uses as much as digits as its factorization.

61809906877 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9144576, while the sum is 61.

The spelling of 61809906877 in words is "sixty-one billion, eight hundred nine million, nine hundred six thousand, eight hundred seventy-seven".