81162800 has 30 divisors (see below), whose sum is σ = 194994588. Its totient is φ = 32464960.

The previous prime is 81162799. The next prime is 81162803. The reversal of 81162800 is 826118.

It is a self number, because there is not a number n which added to its sum of digits gives 81162800.

It is not an unprimeable number, because it can be changed into a prime (81162803) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101054 + ... + 101853.

Almost surely, 2^81162800 is an apocalyptic number.

81162800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81162800 is an abundant number, since it is smaller than the sum of its proper divisors (113831788).

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

81162800 is a wasteful number, since it uses less digits than its factorization.

81162800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202925 (or 202914 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 81162800 is about 9009.0399044515. The cubic root of 81162800 is about 432.9645514630.

Adding to 81162800 its reverse (826118), we get a palindrome (81988918).

The spelling of 81162800 in words is "eighty-one million, one hundred sixty-two thousand, eight hundred".