87809993 has 2 divisors, whose sum is σ = 87809994. Its totient is φ = 87809992.

The previous prime is 87809983. The next prime is 87810017. The reversal of 87809993 is 39990878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60016009 + 27793984 = 7747^2 + 5272^2 .

It is a cyclic number.

It is not a de Polignac number, because 87809993 - 2⁴ = 87809977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (87809903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43904996 + 43904997.

It is an arithmetic number, because the mean of its divisors is an integer number (43904997).

Almost surely, 2^87809993 is an apocalyptic number.

It is an amenable number.

87809993 is a deficient number, since it is larger than the sum of its proper divisors (1).

87809993 is an equidigital number, since it uses as much as digits as its factorization.

87809993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 979776, while the sum is 53.

The square root of 87809993 is about 9370.6986399094. The cubic root of 87809993 is about 444.4756572917.

The spelling of 87809993 in words is "eighty-seven million, eight hundred nine thousand, nine hundred ninety-three".