87993813 has 4 divisors (see below), whose sum is σ = 117325088. Its totient is φ = 58662540.

The previous prime is 87993797. The next prime is 87993817. The reversal of 87993813 is 31839978.

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 not a de Polignac number, because 87993813 - 2⁴ = 87993797 is a prime.

It is a super-2 number, since 2×87993813² = 15485822252557938, 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 (87993817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14665633 + ... + 14665638.

It is an arithmetic number, because the mean of its divisors is an integer number (29331272).

Almost surely, 2^87993813 is an apocalyptic number.

It is an amenable number.

87993813 is a deficient number, since it is larger than the sum of its proper divisors (29331275).

87993813 is a wasteful number, since it uses less digits than its factorization.

87993813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29331274.

The product of its digits is 326592, while the sum is 48.

The square root of 87993813 is about 9380.5017456424. The cubic root of 87993813 is about 444.7855938053.

The spelling of 87993813 in words is "eighty-seven million, nine hundred ninety-three thousand, eight hundred thirteen".