164991787 has 2 divisors, whose sum is σ = 164991788. Its totient is φ = 164991786.

The previous prime is 164991781. The next prime is 164991791. The reversal of 164991787 is 787199461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 164991787 - 2¹¹ = 164989739 is a prime.

It is not a weakly prime, because it can be changed into another prime (164991781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82495893 + 82495894.

It is an arithmetic number, because the mean of its divisors is an integer number (82495894).

Almost surely, 2^164991787 is an apocalyptic number.

164991787 is a deficient number, since it is larger than the sum of its proper divisors (1).

164991787 is an equidigital number, since it uses as much as digits as its factorization.

164991787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 52.

The square root of 164991787 is about 12844.9128840954. The cubic root of 164991787 is about 548.4715547456.

The spelling of 164991787 in words is "one hundred sixty-four million, nine hundred ninety-one thousand, seven hundred eighty-seven".