2187366991 has 2 divisors, whose sum is σ = 2187366992. Its totient is φ = 2187366990.

The previous prime is 2187366959. The next prime is 2187367051. The reversal of 2187366991 is 1996637812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2187366991 - 2⁵ = 2187366959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2187366901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1093683495 + 1093683496.

It is an arithmetic number, because the mean of its divisors is an integer number (1093683496).

Almost surely, 2^2187366991 is an apocalyptic number.

2187366991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2187366991 is an equidigital number, since it uses as much as digits as its factorization.

2187366991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 52.

The square root of 2187366991 is about 46769.2953870379. The cubic root of 2187366991 is about 1298.0972145124.

The spelling of 2187366991 in words is "two billion, one hundred eighty-seven million, three hundred sixty-six thousand, nine hundred ninety-one".