81214046257 has 6 divisors (see below), whose sum is σ = 82978772018. Its totient is φ = 79486085664.

The previous prime is 81214046219. The next prime is 81214046267. The reversal of 81214046257 is 75264041218.

It can be written as a sum of positive squares in only one way, i.e., 76556802721 + 4657243536 = 276689^2 + 68244^2 .

It is not a de Polignac number, because 81214046257 - 2¹¹ = 81214044209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81214046267) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18380328 + ... + 18384745.

Almost surely, 2^81214046257 is an apocalyptic number.

It is an amenable number.

81214046257 is a deficient number, since it is larger than the sum of its proper divisors (1764725761).

81214046257 is an equidigital number, since it uses as much as digits as its factorization.

81214046257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36765167 (or 36765120 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 40.

The spelling of 81214046257 in words is "eighty-one billion, two hundred fourteen million, forty-six thousand, two hundred fifty-seven".