1231220351 has 2 divisors, whose sum is σ = 1231220352. Its totient is φ = 1231220350.

The previous prime is 1231220303. The next prime is 1231220357. The reversal of 1231220351 is 1530221321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1231220351 - 2³⁰ = 157478527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231220357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615610175 + 615610176.

It is an arithmetic number, because the mean of its divisors is an integer number (615610176).

Almost surely, 2^1231220351 is an apocalyptic number.

1231220351 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231220351 is an equidigital number, since it uses as much as digits as its factorization.

1231220351 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1231220351 is about 35088.7496357451. The cubic root of 1231220351 is about 1071.7954979394.

Adding to 1231220351 its reverse (1530221321), we get a palindrome (2761441672).

The spelling of 1231220351 in words is "one billion, two hundred thirty-one million, two hundred twenty thousand, three hundred fifty-one".