81858958 has 8 divisors (see below), whose sum is σ = 123316128. Its totient is φ = 40753584.

The previous prime is 81858947. The next prime is 81858989. The reversal of 81858958 is 85985818.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87366 + ... + 88297.

It is an arithmetic number, because the mean of its divisors is an integer number (15414516).

Almost surely, 2^81858958 is an apocalyptic number.

81858958 is a deficient number, since it is larger than the sum of its proper divisors (41457170).

81858958 is a wasteful number, since it uses less digits than its factorization.

81858958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175898.

The product of its digits is 921600, while the sum is 52.

The square root of 81858958 is about 9047.5940448276. The cubic root of 81858958 is about 434.1989184910.

The spelling of 81858958 in words is "eighty-one million, eight hundred fifty-eight thousand, nine hundred fifty-eight".