61220755091 has 2 divisors, whose sum is σ = 61220755092. Its totient is φ = 61220755090.

The previous prime is 61220755049. The next prime is 61220755151. The reversal of 61220755091 is 19055702216.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61220755091 - 2¹⁸ = 61220492947 is a prime.

It is not a weakly prime, because it can be changed into another prime (61220755021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30610377545 + 30610377546.

It is an arithmetic number, because the mean of its divisors is an integer number (30610377546).

Almost surely, 2^61220755091 is an apocalyptic number.

61220755091 is a deficient number, since it is larger than the sum of its proper divisors (1).

61220755091 is an equidigital number, since it uses as much as digits as its factorization.

61220755091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 38.

The spelling of 61220755091 in words is "sixty-one billion, two hundred twenty million, seven hundred fifty-five thousand, ninety-one".