81236412 has 24 divisors (see below), whose sum is σ = 210613200. Its totient is φ = 27078768.

The previous prime is 81236383. The next prime is 81236413. The reversal of 81236412 is 21463218.

81236412 is a `hidden beast` number, since 8 + 12 + 3 + 641 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81236413) 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, 375987 + ... + 376202.

It is an arithmetic number, because the mean of its divisors is an integer number (8775550).

Almost surely, 2^81236412 is an apocalyptic number.

It is an amenable number.

81236412 is an abundant number, since it is smaller than the sum of its proper divisors (129376788).

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

81236412 is a wasteful number, since it uses less digits than its factorization.

81236412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752202 (or 752194 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 81236412 is about 9013.1244305180. The cubic root of 81236412 is about 433.0954067973.

It can be divided in two parts, 8123 and 6412, that added together give a triangular number (14535 = T₁₇₀).

The spelling of 81236412 in words is "eighty-one million, two hundred thirty-six thousand, four hundred twelve".