1213211591 has 2 divisors, whose sum is σ = 1213211592. Its totient is φ = 1213211590.

The previous prime is 1213211557. The next prime is 1213211603. The reversal of 1213211591 is 1951123121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1213211591 - 2³⁰ = 139469767 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1213211591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213211501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606605795 + 606605796.

It is an arithmetic number, because the mean of its divisors is an integer number (606605796).

Almost surely, 2^1213211591 is an apocalyptic number.

1213211591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213211591 is an equidigital number, since it uses as much as digits as its factorization.

1213211591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 540, while the sum is 26.

The square root of 1213211591 is about 34831.1870455200. The cubic root of 1213211591 is about 1066.5441803472.

The spelling of 1213211591 in words is "one billion, two hundred thirteen million, two hundred eleven thousand, five hundred ninety-one".