61891374893 has 2 divisors, whose sum is σ = 61891374894. Its totient is φ = 61891374892.

The previous prime is 61891374871. The next prime is 61891374899. The reversal of 61891374893 is 39847319816.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47488254724 + 14403120169 = 217918^2 + 120013^2 .

It is a cyclic number.

It is not a de Polignac number, because 61891374893 - 2⁸ = 61891374637 is a prime.

It is a super-2 number, since 2×61891374893² (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 (61891374899) 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, 30945687446 + 30945687447.

It is an arithmetic number, because the mean of its divisors is an integer number (30945687447).

Almost surely, 2^61891374893 is an apocalyptic number.

It is an amenable number.

61891374893 is a deficient number, since it is larger than the sum of its proper divisors (1).

61891374893 is an equidigital number, since it uses as much as digits as its factorization.

61891374893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 59.

The spelling of 61891374893 in words is "sixty-one billion, eight hundred ninety-one million, three hundred seventy-four thousand, eight hundred ninety-three".