81355995 has 40 divisors (see below), whose sum is σ = 166677984. Its totient is φ = 37190016.

The previous prime is 81355979. The next prime is 81356021. The reversal of 81355995 is 59955318.

81355995 is a `hidden beast` number, since 8 + 1 + 3 + 559 + 95 = 666.

It is not a de Polignac number, because 81355995 - 2⁴ = 81355979 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81355995.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11514 + ... + 17183.

Almost surely, 2^81355995 is an apocalyptic number.

81355995 is an abundant number, since it is smaller than the sum of its proper divisors (85321989).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81355995 is a wasteful number, since it uses less digits than its factorization.

81355995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28721 (or 28712 counting only the distinct ones).

The product of its digits is 243000, while the sum is 45.

The square root of 81355995 is about 9019.7558170939. The cubic root of 81355995 is about 433.3078134215.

The spelling of 81355995 in words is "eighty-one million, three hundred fifty-five thousand, nine hundred ninety-five".