81626563 has 8 divisors (see below), whose sum is σ = 85428000. Its totient is φ = 77846208.

The previous prime is 81626533. The next prime is 81626579. The reversal of 81626563 is 36562618.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81626563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81626533) 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, 2943 + ... + 13111.

It is an arithmetic number, because the mean of its divisors is an integer number (10678500).

Almost surely, 2^81626563 is an apocalyptic number.

81626563 is a deficient number, since it is larger than the sum of its proper divisors (3801437).

81626563 is a wasteful number, since it uses less digits than its factorization.

81626563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10541.

The product of its digits is 51840, while the sum is 37.

The square root of 81626563 is about 9034.7419996367. The cubic root of 81626563 is about 433.7876366946.

The spelling of 81626563 in words is "eighty-one million, six hundred twenty-six thousand, five hundred sixty-three".