1221937867 has 2 divisors, whose sum is σ = 1221937868. Its totient is φ = 1221937866.

The previous prime is 1221937853. The next prime is 1221937889. The reversal of 1221937867 is 7687391221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221937867 - 2¹⁹ = 1221413579 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221937567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610968933 + 610968934.

It is an arithmetic number, because the mean of its divisors is an integer number (610968934).

Almost surely, 2^1221937867 is an apocalyptic number.

1221937867 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221937867 is an equidigital number, since it uses as much as digits as its factorization.

1221937867 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 46.

The square root of 1221937867 is about 34956.2278714394. The cubic root of 1221937867 is about 1069.0951872823.

It can be divided in two parts, 12219 and 37867, that added together give a triangular number (50086 = T₃₁₆).

The spelling of 1221937867 in words is "one billion, two hundred twenty-one million, nine hundred thirty-seven thousand, eight hundred sixty-seven".