61515670861 has 2 divisors, whose sum is σ = 61515670862. Its totient is φ = 61515670860.

The previous prime is 61515670831. The next prime is 61515670873. The reversal of 61515670861 is 16807651516.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42324832900 + 19190837961 = 205730^2 + 138531^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61515670861 is a prime.

It is a super-2 number, since 2×61515670861² (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 (61515670831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30757835430 + 30757835431.

It is an arithmetic number, because the mean of its divisors is an integer number (30757835431).

Almost surely, 2^61515670861 is an apocalyptic number.

It is an amenable number.

61515670861 is a deficient number, since it is larger than the sum of its proper divisors (1).

61515670861 is an equidigital number, since it uses as much as digits as its factorization.

61515670861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 302400, while the sum is 46.

The spelling of 61515670861 in words is "sixty-one billion, five hundred fifteen million, six hundred seventy thousand, eight hundred sixty-one".