61275076721 has 2 divisors, whose sum is σ = 61275076722. Its totient is φ = 61275076720.

The previous prime is 61275076717. The next prime is 61275076769. The reversal of 61275076721 is 12767057216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49106560000 + 12168516721 = 221600^2 + 110311^2 .

It is a cyclic number.

It is not a de Polignac number, because 61275076721 - 2² = 61275076717 is a prime.

It is a super-2 number, since 2×61275076721² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61275076781) 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, 30637538360 + 30637538361.

It is an arithmetic number, because the mean of its divisors is an integer number (30637538361).

Almost surely, 2^61275076721 is an apocalyptic number.

It is an amenable number.

61275076721 is a deficient number, since it is larger than the sum of its proper divisors (1).

61275076721 is an equidigital number, since it uses as much as digits as its factorization.

61275076721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 246960, while the sum is 44.

The spelling of 61275076721 in words is "sixty-one billion, two hundred seventy-five million, seventy-six thousand, seven hundred twenty-one".