1231661351 has 2 divisors, whose sum is σ = 1231661352. Its totient is φ = 1231661350.

The previous prime is 1231661323. The next prime is 1231661359. The reversal of 1231661351 is 1531661321.

It is a strong prime.

It is an emirp because it is prime and its reverse (1531661321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1231661351 - 2⁶ = 1231661287 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231661359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615830675 + 615830676.

It is an arithmetic number, because the mean of its divisors is an integer number (615830676).

Almost surely, 2^1231661351 is an apocalyptic number.

1231661351 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231661351 is an equidigital number, since it uses as much as digits as its factorization.

1231661351 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 29.

The square root of 1231661351 is about 35095.0331386081. The cubic root of 1231661351 is about 1071.9234483350.

The spelling of 1231661351 in words is "one billion, two hundred thirty-one million, six hundred sixty-one thousand, three hundred fifty-one".