81200051269 has 2 divisors, whose sum is σ = 81200051270. Its totient is φ = 81200051268.

The previous prime is 81200051239. The next prime is 81200051311. The reversal of 81200051269 is 96215000218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79362214369 + 1837836900 = 281713^2 + 42870^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81200051269 is a prime.

It is a super-2 number, since 2×81200051269² (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 (81200051239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40600025634 + 40600025635.

It is an arithmetic number, because the mean of its divisors is an integer number (40600025635).

Almost surely, 2^81200051269 is an apocalyptic number.

It is an amenable number.

81200051269 is a deficient number, since it is larger than the sum of its proper divisors (1).

81200051269 is an equidigital number, since it uses as much as digits as its factorization.

81200051269 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 34.

The spelling of 81200051269 in words is "eighty-one billion, two hundred million, fifty-one thousand, two hundred sixty-nine".