61451981441 has 2 divisors, whose sum is σ = 61451981442. Its totient is φ = 61451981440.

The previous prime is 61451981401. The next prime is 61451981443. The reversal of 61451981441 is 14418915416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54613353025 + 6838628416 = 233695^2 + 82696^2 .

It is a cyclic number.

It is not a de Polignac number, because 61451981441 - 2⁶ = 61451981377 is a prime.

Together with 61451981443, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 61451981392 and 61451981401.

It is not a weakly prime, because it can be changed into another prime (61451981443) 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, 30725990720 + 30725990721.

It is an arithmetic number, because the mean of its divisors is an integer number (30725990721).

Almost surely, 2^61451981441 is an apocalyptic number.

It is an amenable number.

61451981441 is a deficient number, since it is larger than the sum of its proper divisors (1).

61451981441 is an equidigital number, since it uses as much as digits as its factorization.

61451981441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 138240, while the sum is 44.

The spelling of 61451981441 in words is "sixty-one billion, four hundred fifty-one million, nine hundred eighty-one thousand, four hundred forty-one".