83969981 has 4 divisors (see below), whose sum is σ = 84346752. Its totient is φ = 83593212.

The previous prime is 83969971. The next prime is 83970017. The reversal of 83969981 is 18996938.

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 83969981 - 2¹⁰ = 83968957 is a prime.

It is a super-2 number, since 2×83969981² = 14101915418280722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83969971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 188051 + ... + 188496.

It is an arithmetic number, because the mean of its divisors is an integer number (21086688).

Almost surely, 2^83969981 is an apocalyptic number.

It is an amenable number.

83969981 is a deficient number, since it is larger than the sum of its proper divisors (376771).

83969981 is a wasteful number, since it uses less digits than its factorization.

83969981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376770.

The product of its digits is 839808, while the sum is 53.

The square root of 83969981 is about 9163.5135728606. The cubic root of 83969981 is about 437.8997376201.

The spelling of 83969981 in words is "eighty-three million, nine hundred sixty-nine thousand, nine hundred eighty-one".