61216812977 has 2 divisors, whose sum is σ = 61216812978. Its totient is φ = 61216812976.

The previous prime is 61216812973. The next prime is 61216813079. The reversal of 61216812977 is 77921861216.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57857567296 + 3359245681 = 240536^2 + 57959^2 .

It is a cyclic number.

It is not a de Polignac number, because 61216812977 - 2² = 61216812973 is a prime.

It is not a weakly prime, because it can be changed into another prime (61216812973) 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, 30608406488 + 30608406489.

It is an arithmetic number, because the mean of its divisors is an integer number (30608406489).

Almost surely, 2^61216812977 is an apocalyptic number.

It is an amenable number.

61216812977 is a deficient number, since it is larger than the sum of its proper divisors (1).

61216812977 is an equidigital number, since it uses as much as digits as its factorization.

61216812977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 50.

The spelling of 61216812977 in words is "sixty-one billion, two hundred sixteen million, eight hundred twelve thousand, nine hundred seventy-seven".