81426072 has 128 divisors (see below), whose sum is σ = 261596160. Its totient is φ = 20528640.

The previous prime is 81426029. The next prime is 81426097. The reversal of 81426072 is 27062418.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49422 + ... + 51042.

It is an arithmetic number, because the mean of its divisors is an integer number (2043720).

Almost surely, 2^81426072 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 81426072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130798080).

81426072 is an abundant number, since it is smaller than the sum of its proper divisors (180170088).

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

81426072 is a wasteful number, since it uses less digits than its factorization.

81426072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1673 (or 1669 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 81426072 is about 9023.6396204636. The cubic root of 81426072 is about 433.4321894121.

The spelling of 81426072 in words is "eighty-one million, four hundred twenty-six thousand, seventy-two".