81091426 has 8 divisors (see below), whose sum is σ = 130993884. Its totient is φ = 37426800.

The previous prime is 81091397. The next prime is 81091427. The reversal of 81091426 is 62419018.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 80730225 + 361201 = 8985^2 + 601^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81091427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1559425 + ... + 1559476.

Almost surely, 2^81091426 is an apocalyptic number.

81091426 is a deficient number, since it is larger than the sum of its proper divisors (49902458).

81091426 is a wasteful number, since it uses less digits than its factorization.

81091426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118916.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 81091426 is about 9005.0777897806. The cubic root of 81091426 is about 432.8375989068.

The spelling of 81091426 in words is "eighty-one million, ninety-one thousand, four hundred twenty-six".