87973813 has 2 divisors, whose sum is σ = 87973814. Its totient is φ = 87973812.

The previous prime is 87973751. The next prime is 87973867. The reversal of 87973813 is 31837978.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57426084 + 30547729 = 7578^2 + 5527^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87973813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87973213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43986906 + 43986907.

It is an arithmetic number, because the mean of its divisors is an integer number (43986907).

Almost surely, 2^87973813 is an apocalyptic number.

It is an amenable number.

87973813 is a deficient number, since it is larger than the sum of its proper divisors (1).

87973813 is an equidigital number, since it uses as much as digits as its factorization.

87973813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 46.

The square root of 87973813 is about 9379.4356440033. The cubic root of 87973813 is about 444.7518930044.

The spelling of 87973813 in words is "eighty-seven million, nine hundred seventy-three thousand, eight hundred thirteen".