81022620 has 96 divisors (see below), whose sum is σ = 260467200. Its totient is φ = 18434304.

The previous prime is 81022597. The next prime is 81022633. The reversal of 81022620 is 2622018.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 158926 + ... + 159434.

It is an arithmetic number, because the mean of its divisors is an integer number (2713200).

Almost surely, 2^81022620 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81022620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130233600).

81022620 is an abundant number, since it is smaller than the sum of its proper divisors (179444580).

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

81022620 is a wasteful number, since it uses less digits than its factorization.

81022620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907 (or 905 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 81022620 is about 9001.2565789450. The cubic root of 81022620 is about 432.7151434983.

Adding to 81022620 its reverse (2622018), we get a palindrome (83644638).

The spelling of 81022620 in words is "eighty-one million, twenty-two thousand, six hundred twenty".