83640787 has 4 divisors (see below), whose sum is σ = 83669920. Its totient is φ = 83611656.

The previous prime is 83640773. The next prime is 83640839. The reversal of 83640787 is 78704638.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78704638 = 2 ⋅39352319.

It is a cyclic number.

It is not a de Polignac number, because 83640787 - 2¹¹ = 83638739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (83640707) 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, 9723 + ... + 16180.

It is an arithmetic number, because the mean of its divisors is an integer number (20917480).

Almost surely, 2^83640787 is an apocalyptic number.

83640787 is a deficient number, since it is larger than the sum of its proper divisors (29133).

83640787 is a wasteful number, since it uses less digits than its factorization.

83640787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29132.

The product of its (nonzero) digits is 225792, while the sum is 43.

The square root of 83640787 is about 9145.5337187066. The cubic root of 83640787 is about 437.3267441321.

The spelling of 83640787 in words is "eighty-three million, six hundred forty thousand, seven hundred eighty-seven".