81690323 has 8 divisors (see below), whose sum is σ = 95972016. Its totient is φ = 68551200.

The previous prime is 81690317. The next prime is 81690373. The reversal of 81690323 is 32309618.

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 81690323 - 2⁴ = 81690307 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 81690323.

It is not an unprimeable number, because it can be changed into a prime (81690313) 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, 285488 + ... + 285773.

It is an arithmetic number, because the mean of its divisors is an integer number (11996502).

Almost surely, 2^81690323 is an apocalyptic number.

81690323 is a deficient number, since it is larger than the sum of its proper divisors (14281693).

81690323 is a wasteful number, since it uses less digits than its factorization.

81690323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571285.

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

The square root of 81690323 is about 9038.2699118803. The cubic root of 81690323 is about 433.9005537825.

The spelling of 81690323 in words is "eighty-one million, six hundred ninety thousand, three hundred twenty-three".