81090734 has 4 divisors (see below), whose sum is σ = 121636104. Its totient is φ = 40545366.

The previous prime is 81090677. The next prime is 81090749. The reversal of 81090734 is 43709018.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81090734.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20272682 + ... + 20272685.

It is an arithmetic number, because the mean of its divisors is an integer number (30409026).

Almost surely, 2^81090734 is an apocalyptic number.

81090734 is a deficient number, since it is larger than the sum of its proper divisors (40545370).

81090734 is a wasteful number, since it uses less digits than its factorization.

81090734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40545369.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 81090734 is about 9005.0393669323. The cubic root of 81090734 is about 432.8363676855.

The spelling of 81090734 in words is "eighty-one million, ninety thousand, seven hundred thirty-four".