81630923 has 8 divisors (see below), whose sum is σ = 94290480. Its totient is φ = 69844480.

The previous prime is 81630919. The next prime is 81630929. The reversal of 81630923 is 32903618.

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 81630923 - 2² = 81630919 is a prime.

It is an alternating number because its digits alternate between even and odd.

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 81630923.

It is not an unprimeable number, because it can be changed into a prime (81630929) 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, 218078 + ... + 218451.

It is an arithmetic number, because the mean of its divisors is an integer number (11786310).

Almost surely, 2^81630923 is an apocalyptic number.

81630923 is a deficient number, since it is larger than the sum of its proper divisors (12659557).

81630923 is a wasteful number, since it uses less digits than its factorization.

81630923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436557.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 81630923 is about 9034.9832872009. The cubic root of 81630923 is about 433.7953599992.

The spelling of 81630923 in words is "eighty-one million, six hundred thirty thousand, nine hundred twenty-three".