1243453901 has 2 divisors, whose sum is σ = 1243453902. Its totient is φ = 1243453900.

The previous prime is 1243453867. The next prime is 1243453903. The reversal of 1243453901 is 1093543421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1025920900 + 217533001 = 32030^2 + 14749^2 .

It is an emirp because it is prime and its reverse (1093543421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1243453901 - 2⁶ = 1243453837 is a prime.

Together with 1243453903, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243453903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621726950 + 621726951.

It is an arithmetic number, because the mean of its divisors is an integer number (621726951).

Almost surely, 2^1243453901 is an apocalyptic number.

It is an amenable number.

1243453901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243453901 is an equidigital number, since it uses as much as digits as its factorization.

1243453901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 1243453901 is about 35262.6417189637. The cubic root of 1243453901 is about 1075.3336338873. Note that the first 3 decimals are identical.

The spelling of 1243453901 in words is "one billion, two hundred forty-three million, four hundred fifty-three thousand, nine hundred one".