81230900 has 18 divisors (see below), whose sum is σ = 176271270. Its totient is φ = 32492320.

The previous prime is 81230893. The next prime is 81230921. The reversal of 81230900 is 903218.

It can be written as a sum of positive squares in 3 ways, for example, as 1056784 + 80174116 = 1028^2 + 8954^2 .

It is a super-2 number, since 2×81230900² = 13196918229620000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 406055 + ... + 406254.

Almost surely, 2^81230900 is an apocalyptic number.

It is an amenable number.

81230900 is an abundant number, since it is smaller than the sum of its proper divisors (95040370).

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

81230900 is a wasteful number, since it uses less digits than its factorization.

81230900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812323 (or 812316 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 81230900 is about 9012.8186490132. The cubic root of 81230900 is about 433.0856112068.

The spelling of 81230900 in words is "eighty-one million, two hundred thirty thousand, nine hundred".