61740865621 has 2 divisors, whose sum is σ = 61740865622. Its totient is φ = 61740865620.

The previous prime is 61740865583. The next prime is 61740865631. The reversal of 61740865621 is 12656804716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57326724900 + 4414140721 = 239430^2 + 66439^2 .

It is a cyclic number.

It is not a de Polignac number, because 61740865621 - 2¹³ = 61740857429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61740865631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30870432810 + 30870432811.

It is an arithmetic number, because the mean of its divisors is an integer number (30870432811).

Almost surely, 2^61740865621 is an apocalyptic number.

It is an amenable number.

61740865621 is a deficient number, since it is larger than the sum of its proper divisors (1).

61740865621 is an equidigital number, since it uses as much as digits as its factorization.

61740865621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 61740865621 in words is "sixty-one billion, seven hundred forty million, eight hundred sixty-five thousand, six hundred twenty-one".