1222156813 has 2 divisors, whose sum is σ = 1222156814. Its totient is φ = 1222156812.

The previous prime is 1222156787. The next prime is 1222156829. The reversal of 1222156813 is 3186512221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1209787524 + 12369289 = 34782^2 + 3517^2 .

It is a cyclic number.

It is not a de Polignac number, because 1222156813 - 2¹⁷ = 1222025741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1222126813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 611078406 + 611078407.

It is an arithmetic number, because the mean of its divisors is an integer number (611078407).

Almost surely, 2^1222156813 is an apocalyptic number.

It is an amenable number.

1222156813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1222156813 is an equidigital number, since it uses as much as digits as its factorization.

1222156813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 31.

The square root of 1222156813 is about 34959.3594477931. The cubic root of 1222156813 is about 1069.1590367197.

The spelling of 1222156813 in words is "one billion, two hundred twenty-two million, one hundred fifty-six thousand, eight hundred thirteen".