26019817861 has 2 divisors, whose sum is σ = 26019817862. Its totient is φ = 26019817860.

The previous prime is 26019817801. The next prime is 26019817963. The reversal of 26019817861 is 16871891062.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23323092961 + 2696724900 = 152719^2 + 51930^2 .

It is a cyclic number.

It is not a de Polignac number, because 26019817861 - 2¹⁵ = 26019785093 is a prime.

It is a super-2 number, since 2×26019817861² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26019817801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13009908930 + 13009908931.

It is an arithmetic number, because the mean of its divisors is an integer number (13009908931).

Almost surely, 2^26019817861 is an apocalyptic number.

It is an amenable number.

26019817861 is a deficient number, since it is larger than the sum of its proper divisors (1).

26019817861 is an equidigital number, since it uses as much as digits as its factorization.

26019817861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 49.

The spelling of 26019817861 in words is "twenty-six billion, nineteen million, eight hundred seventeen thousand, eight hundred sixty-one".