1220523391 has 2 divisors, whose sum is σ = 1220523392. Its totient is φ = 1220523390.

The previous prime is 1220523287. The next prime is 1220523397. The reversal of 1220523391 is 1933250221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1220523391 - 2⁷ = 1220523263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220523397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610261695 + 610261696.

It is an arithmetic number, because the mean of its divisors is an integer number (610261696).

Almost surely, 2^1220523391 is an apocalyptic number.

1220523391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220523391 is an equidigital number, since it uses as much as digits as its factorization.

1220523391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 1220523391 is about 34935.9899101199. The cubic root of 1220523391 is about 1068.6825112656.

The spelling of 1220523391 in words is "one billion, two hundred twenty million, five hundred twenty-three thousand, three hundred ninety-one".