81029868 has 12 divisors (see below), whose sum is σ = 189069720. Its totient is φ = 27009952.

The previous prime is 81029849. The next prime is 81029869. The reversal of 81029868 is 86892018.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (81029869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3376233 + ... + 3376256.

It is an arithmetic number, because the mean of its divisors is an integer number (15755810).

Almost surely, 2^81029868 is an apocalyptic number.

It is an amenable number.

81029868 is an abundant number, since it is smaller than the sum of its proper divisors (108039852).

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

81029868 is a wasteful number, since it uses less digits than its factorization.

81029868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6752496 (or 6752494 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 81029868 is about 9001.6591803956. The cubic root of 81029868 is about 432.7280461743.

The spelling of 81029868 in words is "eighty-one million, twenty-nine thousand, eight hundred sixty-eight".