81353822187 has 32 divisors (see below), whose sum is σ = 121571861760. Its totient is φ = 47956648320.

The previous prime is 81353822183. The next prime is 81353822197. The reversal of 81353822187 is 78122835318.

It is not a de Polignac number, because 81353822187 - 2² = 81353822183 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81353822183) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4304364 + ... + 4323222.

It is an arithmetic number, because the mean of its divisors is an integer number (3799120680).

Almost surely, 2^81353822187 is an apocalyptic number.

81353822187 is a deficient number, since it is larger than the sum of its proper divisors (40218039573).

81353822187 is a wasteful number, since it uses less digits than its factorization.

81353822187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22443.

The product of its digits is 645120, while the sum is 48.

The spelling of 81353822187 in words is "eighty-one billion, three hundred fifty-three million, eight hundred twenty-two thousand, one hundred eighty-seven".