203449581581 has 2 divisors, whose sum is σ = 203449581582. Its totient is φ = 203449581580.

The previous prime is 203449581443. The next prime is 203449581631. The reversal of 203449581581 is 185185944302.

It is an a-pointer prime, because the next prime (203449581631) can be obtained adding 203449581581 to its sum of digits (50).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126003700900 + 77445880681 = 354970^2 + 278291^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-203449581581 is a prime.

It is a super-2 number, since 2×203449581581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (203449581781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101724790790 + 101724790791.

It is an arithmetic number, because the mean of its divisors is an integer number (101724790791).

Almost surely, 2^203449581581 is an apocalyptic number.

It is an amenable number.

203449581581 is a deficient number, since it is larger than the sum of its proper divisors (1).

203449581581 is an equidigital number, since it uses as much as digits as its factorization.

203449581581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1382400, while the sum is 50.

The spelling of 203449581581 in words is "two hundred three billion, four hundred forty-nine million, five hundred eighty-one thousand, five hundred eighty-one".