81296020 has 24 divisors (see below), whose sum is σ = 183854664. Its totient is φ = 30016896.

The previous prime is 81295999. The next prime is 81296021. The reversal of 81296020 is 2069218.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18284176 + 63011844 = 4276^2 + 7938^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81296020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81296021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156079 + ... + 156598.

It is an arithmetic number, because the mean of its divisors is an integer number (7660611).

Almost surely, 2^81296020 is an apocalyptic number.

It is an amenable number.

81296020 is an abundant number, since it is smaller than the sum of its proper divisors (102558644).

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

81296020 is a wasteful number, since it uses less digits than its factorization.

81296020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312699 (or 312697 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 81296020 is about 9016.4305575987. The cubic root of 81296020 is about 433.2013102081.

The spelling of 81296020 in words is "eighty-one million, two hundred ninety-six thousand, twenty".