83687021 has 4 divisors (see below), whose sum is σ = 91294944. Its totient is φ = 76079100.

The previous prime is 83687017. The next prime is 83687033. The reversal of 83687021 is 12078638.

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 83687021 - 2² = 83687017 is a prime.

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 (83687521) 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, 3803945 + ... + 3803966.

It is an arithmetic number, because the mean of its divisors is an integer number (22823736).

Almost surely, 2^83687021 is an apocalyptic number.

It is an amenable number.

83687021 is a deficient number, since it is larger than the sum of its proper divisors (7607923).

83687021 is a wasteful number, since it uses less digits than its factorization.

83687021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7607922.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 83687021 is about 9148.0610513923. The cubic root of 83687021 is about 437.4073094520.

The spelling of 83687021 in words is "eighty-three million, six hundred eighty-seven thousand, twenty-one".