1262220991 has 2 divisors, whose sum is σ = 1262220992. Its totient is φ = 1262220990.

The previous prime is 1262220919. The next prime is 1262221001. The reversal of 1262220991 is 1990222621.

Together with previous prime (1262220919) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1262220991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1262220191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631110495 + 631110496.

It is an arithmetic number, because the mean of its divisors is an integer number (631110496).

Almost surely, 2^1262220991 is an apocalyptic number.

1262220991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1262220991 is an equidigital number, since it uses as much as digits as its factorization.

1262220991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 1262220991 is about 35527.7495909887. The cubic root of 1262220991 is about 1080.7165429546.

The spelling of 1262220991 in words is "one billion, two hundred sixty-two million, two hundred twenty thousand, nine hundred ninety-one".