16503111250261 has 2 divisors, whose sum is σ = 16503111250262. Its totient is φ = 16503111250260.

The previous prime is 16503111250259. The next prime is 16503111250319. The reversal of 16503111250261 is 16205211130561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13974931749636 + 2528179500625 = 3738306^2 + 1590025^2 .

It is a cyclic number.

It is not a de Polignac number, because 16503111250261 - 2¹ = 16503111250259 is a prime.

Together with 16503111250259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16503111250201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8251555625130 + 8251555625131.

It is an arithmetic number, because the mean of its divisors is an integer number (8251555625131).

Almost surely, 2^{16503111250261} is an apocalyptic number.

It is an amenable number.

16503111250261 is a deficient number, since it is larger than the sum of its proper divisors (1).

16503111250261 is an equidigital number, since it uses as much as digits as its factorization.

16503111250261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 16503111250261 in words is "sixteen trillion, five hundred three billion, one hundred eleven million, two hundred fifty thousand, two hundred sixty-one".