82187993 has 4 divisors (see below), whose sum is σ = 85761408. Its totient is φ = 78614580.

The previous prime is 82187983. The next prime is 82188019. The reversal of 82187993 is 39978128.

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 82187993 - 2¹⁶ = 82122457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (82187933) 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, 1786673 + ... + 1786718.

It is an arithmetic number, because the mean of its divisors is an integer number (21440352).

Almost surely, 2^82187993 is an apocalyptic number.

It is an amenable number.

82187993 is a deficient number, since it is larger than the sum of its proper divisors (3573415).

82187993 is a wasteful number, since it uses less digits than its factorization.

82187993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3573414.

The product of its digits is 217728, while the sum is 47.

The square root of 82187993 is about 9065.7593724961. The cubic root of 82187993 is about 434.7799001036.

The spelling of 82187993 in words is "eighty-two million, one hundred eighty-seven thousand, nine hundred ninety-three".