81213876 has 36 divisors (see below), whose sum is σ = 205706592. Its totient is φ = 27016464.

The previous prime is 81213871. The next prime is 81213889. The reversal of 81213876 is 67831218.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81213876.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81213871) 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, 18265 + ... + 22271.

It is an arithmetic number, because the mean of its divisors is an integer number (5714072).

Almost surely, 2^81213876 is an apocalyptic number.

It is an amenable number.

81213876 is an abundant number, since it is smaller than the sum of its proper divisors (124492716).

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

81213876 is a wasteful number, since it uses less digits than its factorization.

81213876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4580 (or 4575 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 81213876 is about 9011.8741668978. The cubic root of 81213876 is about 433.0553543933.

The spelling of 81213876 in words is "eighty-one million, two hundred thirteen thousand, eight hundred seventy-six".