87843991 has 2 divisors, whose sum is σ = 87843992. Its totient is φ = 87843990.

The previous prime is 87843967. The next prime is 87843997. The reversal of 87843991 is 19934878.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 87843991 - 2¹⁵ = 87811223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87843997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43921995 + 43921996.

It is an arithmetic number, because the mean of its divisors is an integer number (43921996).

Almost surely, 2^87843991 is an apocalyptic number.

87843991 is a deficient number, since it is larger than the sum of its proper divisors (1).

87843991 is an equidigital number, since it uses as much as digits as its factorization.

87843991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 49.

The square root of 87843991 is about 9372.5125233312. The cubic root of 87843991 is about 444.5330134576.

The spelling of 87843991 in words is "eighty-seven million, eight hundred forty-three thousand, nine hundred ninety-one".