81953056899 has 12 divisors (see below), whose sum is σ = 135287586096. Its totient is φ = 46830318192.

The previous prime is 81953056879. The next prime is 81953056951. The reversal of 81953056899 is 99865035918.

81953056899 is a `hidden beast` number, since 8 + 1 + 9 + 530 + 5 + 6 + 8 + 99 = 666.

It is not a de Polignac number, because 81953056899 - 2⁷ = 81953056771 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 1300842173 = 81953056899 / (8 + 1 + 9 + 5 + 3 + 0 + 5 + 6 + 8 + 9 + 9).

It is not an unprimeable number, because it can be changed into a prime (81953056819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 650421024 + ... + 650421149.

It is an arithmetic number, because the mean of its divisors is an integer number (11273965508).

Almost surely, 2^81953056899 is an apocalyptic number.

81953056899 is a deficient number, since it is larger than the sum of its proper divisors (53334529197).

81953056899 is a wasteful number, since it uses less digits than its factorization.

81953056899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300842186 (or 1300842183 counting only the distinct ones).

The product of its (nonzero) digits is 20995200, while the sum is 63.

The spelling of 81953056899 in words is "eighty-one billion, nine hundred fifty-three million, fifty-six thousand, eight hundred ninety-nine".