81036920 has 16 divisors (see below), whose sum is σ = 182333160. Its totient is φ = 32414752.

The previous prime is 81036863. The next prime is 81036941. The reversal of 81036920 is 2963018.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1012922 + ... + 1013001.

Almost surely, 2^81036920 is an apocalyptic number.

It is an amenable number.

81036920 is an abundant number, since it is smaller than the sum of its proper divisors (101296240).

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

81036920 is a wasteful number, since it uses less digits than its factorization.

81036920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2025934 (or 2025930 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 81036920 is about 9002.0508774390. The cubic root of 81036920 is about 432.7405991984.

Adding to 81036920 its reverse (2963018), we get a palindrome (83999938).

The spelling of 81036920 in words is "eighty-one million, thirty-six thousand, nine hundred twenty".