203454421421 has 2 divisors, whose sum is σ = 203454421422. Its totient is φ = 203454421420.

The previous prime is 203454421409. The next prime is 203454421427. The reversal of 203454421421 is 124124454302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198105108100 + 5349313321 = 445090^2 + 73139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-203454421421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (203454421427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101727210710 + 101727210711.

It is an arithmetic number, because the mean of its divisors is an integer number (101727210711).

Almost surely, 2^203454421421 is an apocalyptic number.

It is an amenable number.

203454421421 is a deficient number, since it is larger than the sum of its proper divisors (1).

203454421421 is an equidigital number, since it uses as much as digits as its factorization.

203454421421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30720, while the sum is 32.

Adding to 203454421421 its reverse (124124454302), we get a palindrome (327578875723).

The spelling of 203454421421 in words is "two hundred three billion, four hundred fifty-four million, four hundred twenty-one thousand, four hundred twenty-one".