61656500909 has 2 divisors, whose sum is σ = 61656500910. Its totient is φ = 61656500908.

The previous prime is 61656500879. The next prime is 61656500987. The reversal of 61656500909 is 90900565616.

61656500909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59755802500 + 1900698409 = 244450^2 + 43597^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61656500909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61656500509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30828250454 + 30828250455.

It is an arithmetic number, because the mean of its divisors is an integer number (30828250455).

Almost surely, 2^61656500909 is an apocalyptic number.

It is an amenable number.

61656500909 is a deficient number, since it is larger than the sum of its proper divisors (1).

61656500909 is an equidigital number, since it uses as much as digits as its factorization.

61656500909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 437400, while the sum is 47.

The spelling of 61656500909 in words is "sixty-one billion, six hundred fifty-six million, five hundred thousand, nine hundred nine".