1225555291 has 2 divisors, whose sum is σ = 1225555292. Its totient is φ = 1225555290.

The previous prime is 1225555259. The next prime is 1225555319. The reversal of 1225555291 is 1925555221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1225555291 - 2⁵ = 1225555259 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1225555291.

It is not a weakly prime, because it can be changed into another prime (1225555091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612777645 + 612777646.

It is an arithmetic number, because the mean of its divisors is an integer number (612777646).

Almost surely, 2^1225555291 is an apocalyptic number.

1225555291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225555291 is an equidigital number, since it uses as much as digits as its factorization.

1225555291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45000, while the sum is 37.

The square root of 1225555291 is about 35007.9318298011. The cubic root of 1225555291 is about 1070.1491308138.

It can be divided in two parts, 1225 and 555291, that added together give a square (556516 = 746²).

The spelling of 1225555291 in words is "one billion, two hundred twenty-five million, five hundred fifty-five thousand, two hundred ninety-one".