81057623 has 8 divisors (see below), whose sum is σ = 83601408. Its totient is φ = 78543864.

The previous prime is 81057583. The next prime is 81057637. The reversal of 81057623 is 32675018.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81057623 - 2⁸ = 81057367 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81057623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81057643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1961 + ... + 12882.

It is an arithmetic number, because the mean of its divisors is an integer number (10450176).

Almost surely, 2^81057623 is an apocalyptic number.

81057623 is a deficient number, since it is larger than the sum of its proper divisors (2543785).

81057623 is a wasteful number, since it uses less digits than its factorization.

81057623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15013.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 81057623 is about 9003.2007086369. The cubic root of 81057623 is about 432.7774476941. Note that the first 3 decimals are identical.

The spelling of 81057623 in words is "eighty-one million, fifty-seven thousand, six hundred twenty-three".