1231978453 has 2 divisors, whose sum is σ = 1231978454. Its totient is φ = 1231978452.

The previous prime is 1231978403. The next prime is 1231978483. The reversal of 1231978453 is 3548791321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1223810289 + 8168164 = 34983^2 + 2858^2 .

It is an emirp because it is prime and its reverse (3548791321) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231978453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231978403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615989226 + 615989227.

It is an arithmetic number, because the mean of its divisors is an integer number (615989227).

Almost surely, 2^1231978453 is an apocalyptic number.

It is an amenable number.

1231978453 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231978453 is an equidigital number, since it uses as much as digits as its factorization.

1231978453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 43.

The square root of 1231978453 is about 35099.5506096588. The cubic root of 1231978453 is about 1072.0154324675.

The spelling of 1231978453 in words is "one billion, two hundred thirty-one million, nine hundred seventy-eight thousand, four hundred fifty-three".