81403420 has 48 divisors (see below), whose sum is σ = 196555968. Its totient is φ = 27740160.

The previous prime is 81403411. The next prime is 81403423. The reversal of 81403420 is 2430418.

It is a junction number, because it is equal to n+sod(n) for n = 81403391 and 81403400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81403423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22540 + ... + 25900.

It is an arithmetic number, because the mean of its divisors is an integer number (4094916).

Almost surely, 2^81403420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81403420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98277984).

81403420 is an abundant number, since it is smaller than the sum of its proper divisors (115152548).

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

81403420 is a wasteful number, since it uses less digits than its factorization.

81403420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3550 (or 3548 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 81403420 is about 9022.3843855158. The cubic root of 81403420 is about 433.3919933738.

Adding to 81403420 its reverse (2430418), we get a palindrome (83833838).

The spelling of 81403420 in words is "eighty-one million, four hundred three thousand, four hundred twenty".