61617164821 has 2 divisors, whose sum is σ = 61617164822. Its totient is φ = 61617164820.

The previous prime is 61617164813. The next prime is 61617164827. The reversal of 61617164821 is 12846171616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61412274225 + 204890596 = 247815^2 + 14314^2 .

It is a cyclic number.

It is not a de Polignac number, because 61617164821 - 2³ = 61617164813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61617164827) 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, 30808582410 + 30808582411.

It is an arithmetic number, because the mean of its divisors is an integer number (30808582411).

Almost surely, 2^61617164821 is an apocalyptic number.

It is an amenable number.

61617164821 is a deficient number, since it is larger than the sum of its proper divisors (1).

61617164821 is an equidigital number, since it uses as much as digits as its factorization.

61617164821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The spelling of 61617164821 in words is "sixty-one billion, six hundred seventeen million, one hundred sixty-four thousand, eight hundred twenty-one".