83867821 has 4 divisors (see below), whose sum is σ = 87514272. Its totient is φ = 80221372.

The previous prime is 83867801. The next prime is 83867869. The reversal of 83867821 is 12876838.

It is a happy number.

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 83867821 - 2⁹ = 83867309 is a prime.

It is a super-2 number, since 2×83867821² = 14067622798576082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83867801) 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, 1823191 + ... + 1823236.

It is an arithmetic number, because the mean of its divisors is an integer number (21878568).

Almost surely, 2^83867821 is an apocalyptic number.

It is an amenable number.

83867821 is a deficient number, since it is larger than the sum of its proper divisors (3646451).

83867821 is a wasteful number, since it uses less digits than its factorization.

83867821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3646450.

The product of its digits is 129024, while the sum is 43.

The square root of 83867821 is about 9157.9375953323. The cubic root of 83867821 is about 437.7220789251.

The spelling of 83867821 in words is "eighty-three million, eight hundred sixty-seven thousand, eight hundred twenty-one".