61221393934849 has 2 divisors, whose sum is σ = 61221393934850. Its totient is φ = 61221393934848.

The previous prime is 61221393934747. The next prime is 61221393934867. The reversal of 61221393934849 is 94843939312216.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54208467769600 + 7012926165249 = 7362640^2 + 2648193^2 .

It is a cyclic number.

It is not a de Polignac number, because 61221393934849 - 2¹³ = 61221393926657 is a prime.

It is not a weakly prime, because it can be changed into another prime (61221393931849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30610696967424 + 30610696967425.

It is an arithmetic number, because the mean of its divisors is an integer number (30610696967425).

Almost surely, 2^{61221393934849} is an apocalyptic number.

It is an amenable number.

61221393934849 is a deficient number, since it is larger than the sum of its proper divisors (1).

61221393934849 is an equidigital number, since it uses as much as digits as its factorization.

61221393934849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60466176, while the sum is 64.

The spelling of 61221393934849 in words is "sixty-one trillion, two hundred twenty-one billion, three hundred ninety-three million, nine hundred thirty-four thousand, eight hundred forty-nine".