81620083 has 4 divisors (see below), whose sum is σ = 81640120. Its totient is φ = 81600048.

The previous prime is 81620057. The next prime is 81620087. The reversal of 81620083 is 38002618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81620083 - 2¹⁷ = 81489011 is a prime.

It is a super-3 number, since 3×81620083³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81620087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1485 + ... + 12862.

It is an arithmetic number, because the mean of its divisors is an integer number (20410030).

Almost surely, 2^81620083 is an apocalyptic number.

81620083 is a deficient number, since it is larger than the sum of its proper divisors (20037).

81620083 is a wasteful number, since it uses less digits than its factorization.

81620083 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20036.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 81620083 is about 9034.3833768553. The cubic root of 81620083 is about 433.7761575136.

The spelling of 81620083 in words is "eighty-one million, six hundred twenty thousand, eighty-three".