83821687 has 16 divisors (see below), whose sum is σ = 89740800. Its totient is φ = 78140160.

The previous prime is 83821681. The next prime is 83821693. The reversal of 83821687 is 78612838.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (83821681) and next prime (83821693).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-83821687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83821681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 204739 + ... + 205147.

It is an arithmetic number, because the mean of its divisors is an integer number (5608800).

Almost surely, 2^83821687 is an apocalyptic number.

83821687 is a deficient number, since it is larger than the sum of its proper divisors (5919113).

83821687 is a wasteful number, since it uses less digits than its factorization.

83821687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666.

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

The square root of 83821687 is about 9155.4184502949. The cubic root of 83821687 is about 437.6418035027.

The spelling of 83821687 in words is "eighty-three million, eight hundred twenty-one thousand, six hundred eighty-seven".