1221862997 has 2 divisors, whose sum is σ = 1221862998. Its totient is φ = 1221862996.

The previous prime is 1221862991. The next prime is 1221863023. The reversal of 1221862997 is 7992681221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1102638436 + 119224561 = 33206^2 + 10919^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221862997 - 2¹⁰ = 1221861973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221862991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610931498 + 610931499.

It is an arithmetic number, because the mean of its divisors is an integer number (610931499).

Almost surely, 2^1221862997 is an apocalyptic number.

It is an amenable number.

1221862997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221862997 is an equidigital number, since it uses as much as digits as its factorization.

1221862997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 47.

The square root of 1221862997 is about 34955.1569442908. The cubic root of 1221862997 is about 1069.0733518045.

The spelling of 1221862997 in words is "one billion, two hundred twenty-one million, eight hundred sixty-two thousand, nine hundred ninety-seven".