81821622 has 16 divisors (see below), whose sum is σ = 163748592. Its totient is φ = 27256320.

The previous prime is 81821611. The next prime is 81821627. The reversal of 81821622 is 22612818.

It is a super-3 number, since 3×81821622³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81821622.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81821627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8722 + ... + 15482.

It is an arithmetic number, because the mean of its divisors is an integer number (10234287).

Almost surely, 2^81821622 is an apocalyptic number.

81821622 is an abundant number, since it is smaller than the sum of its proper divisors (81926970).

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

81821622 is a wasteful number, since it uses less digits than its factorization.

81821622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8783.

The product of its digits is 3072, while the sum is 30.

The square root of 81821622 is about 9045.5304985390. The cubic root of 81821622 is about 434.1328955148.

The spelling of 81821622 in words is "eighty-one million, eight hundred twenty-one thousand, six hundred twenty-two".