83891621 has 4 divisors (see below), whose sum is σ = 91518144. Its totient is φ = 76265100.

The previous prime is 83891597. The next prime is 83891623. The reversal of 83891621 is 12619838.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 83891621 - 2¹⁴ = 83875237 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83891623) 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, 3813245 + ... + 3813266.

It is an arithmetic number, because the mean of its divisors is an integer number (22879536).

Almost surely, 2^83891621 is an apocalyptic number.

It is an amenable number.

83891621 is a deficient number, since it is larger than the sum of its proper divisors (7626523).

83891621 is a wasteful number, since it uses less digits than its factorization.

83891621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7626522.

The product of its digits is 20736, while the sum is 38.

The square root of 83891621 is about 9159.2369223642. The cubic root of 83891621 is about 437.7634805818.

The spelling of 83891621 in words is "eighty-three million, eight hundred ninety-one thousand, six hundred twenty-one".