87809213 has 4 divisors (see below), whose sum is σ = 87984288. Its totient is φ = 87634140.

The previous prime is 87809209. The next prime is 87809231. The reversal of 87809213 is 31290878.

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 87809213 - 2² = 87809209 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 (87809263) 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, 86783 + ... + 87788.

It is an arithmetic number, because the mean of its divisors is an integer number (21996072).

Almost surely, 2^87809213 is an apocalyptic number.

It is an amenable number.

87809213 is a deficient number, since it is larger than the sum of its proper divisors (175075).

87809213 is a wasteful number, since it uses less digits than its factorization.

87809213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175074.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 87809213 is about 9370.6570207217. The cubic root of 87809213 is about 444.4743412227.

The spelling of 87809213 in words is "eighty-seven million, eight hundred nine thousand, two hundred thirteen".