87320491 has 4 divisors (see below), whose sum is σ = 87339184. Its totient is φ = 87301800.

The previous prime is 87320377. The next prime is 87320507. The reversal of 87320491 is 19402378.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 87320491 - 2⁹ = 87319979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87320291) 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, 4426 + ... + 13936.

It is an arithmetic number, because the mean of its divisors is an integer number (21834796).

Almost surely, 2^87320491 is an apocalyptic number.

87320491 is a deficient number, since it is larger than the sum of its proper divisors (18693).

87320491 is an equidigital number, since it uses as much as digits as its factorization.

87320491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18692.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 87320491 is about 9344.5433810326. The cubic root of 87320491 is about 443.6481991961.

The spelling of 87320491 in words is "eighty-seven million, three hundred twenty thousand, four hundred ninety-one".