81264020 has 24 divisors (see below), whose sum is σ = 176160768. Its totient is φ = 31456800.

The previous prime is 81264019. The next prime is 81264059. The reversal of 81264020 is 2046218.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64916 + ... + 66155.

It is an arithmetic number, because the mean of its divisors is an integer number (7340032).

Almost surely, 2^81264020 is an apocalyptic number.

It is an amenable number.

81264020 is an abundant number, since it is smaller than the sum of its proper divisors (94896748).

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

81264020 is a wasteful number, since it uses less digits than its factorization.

81264020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131111 (or 131109 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 81264020 is about 9014.6558447896. The cubic root of 81264020 is about 433.1444633859.

The spelling of 81264020 in words is "eighty-one million, two hundred sixty-four thousand, twenty".