203251445561 has 2 divisors, whose sum is σ = 203251445562. Its totient is φ = 203251445560.

The previous prime is 203251445543. The next prime is 203251445587. The reversal of 203251445561 is 165544152302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196634599225 + 6616846336 = 443435^2 + 81344^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-203251445561 is a prime.

It is a super-4 number, since 4×203251445561⁴ (a number of 46 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (203251445591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101625722780 + 101625722781.

It is an arithmetic number, because the mean of its divisors is an integer number (101625722781).

Almost surely, 2^203251445561 is an apocalyptic number.

It is an amenable number.

203251445561 is a deficient number, since it is larger than the sum of its proper divisors (1).

203251445561 is an equidigital number, since it uses as much as digits as its factorization.

203251445561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144000, while the sum is 38.

Adding to 203251445561 its reverse (165544152302), we get a palindrome (368795597863).

The spelling of 203251445561 in words is "two hundred three billion, two hundred fifty-one million, four hundred forty-five thousand, five hundred sixty-one".