1221793151 has 2 divisors, whose sum is σ = 1221793152. Its totient is φ = 1221793150.

The previous prime is 1221793147. The next prime is 1221793201. The reversal of 1221793151 is 1513971221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221793151 - 2² = 1221793147 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221793141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610896575 + 610896576.

It is an arithmetic number, because the mean of its divisors is an integer number (610896576).

Almost surely, 2^1221793151 is an apocalyptic number.

1221793151 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221793151 is an equidigital number, since it uses as much as digits as its factorization.

1221793151 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 32.

The square root of 1221793151 is about 34954.1578499611. The cubic root of 1221793151 is about 1069.0529807481.

The spelling of 1221793151 in words is "one billion, two hundred twenty-one million, seven hundred ninety-three thousand, one hundred fifty-one".