81620703 has 20 divisors (see below), whose sum is σ = 126135240. Its totient is φ = 52535952.

The previous prime is 81620701. The next prime is 81620711. The reversal of 81620703 is 30702618.

It is not a de Polignac number, because 81620703 - 2¹ = 81620701 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81620701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15025 + ... + 19722.

It is an arithmetic number, because the mean of its divisors is an integer number (6306762).

Almost surely, 2^81620703 is an apocalyptic number.

81620703 is a deficient number, since it is larger than the sum of its proper divisors (44514537).

81620703 is a wasteful number, since it uses less digits than its factorization.

81620703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34788 (or 34779 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 81620703 is about 9034.4176901447. The cubic root of 81620703 is about 433.7772558566. Note that the first 3 decimals are identical.

The spelling of 81620703 in words is "eighty-one million, six hundred twenty thousand, seven hundred three".