87787991 has 2 divisors, whose sum is σ = 87787992. Its totient is φ = 87787990.

The previous prime is 87787951. The next prime is 87788083. The reversal of 87787991 is 19978778.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87787991 - 2¹⁰ = 87786967 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87787951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43893995 + 43893996.

It is an arithmetic number, because the mean of its divisors is an integer number (43893996).

Almost surely, 2^87787991 is an apocalyptic number.

87787991 is a deficient number, since it is larger than the sum of its proper divisors (1).

87787991 is an equidigital number, since it uses as much as digits as its factorization.

87787991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 56.

The square root of 87787991 is about 9369.5245877259. The cubic root of 87787991 is about 444.4385310301.

The spelling of 87787991 in words is "eighty-seven million, seven hundred eighty-seven thousand, nine hundred ninety-one".