266430991 has 2 divisors, whose sum is σ = 266430992. Its totient is φ = 266430990.

The previous prime is 266430973. The next prime is 266431001. The reversal of 266430991 is 199034662.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-266430991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266430911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133215495 + 133215496.

It is an arithmetic number, because the mean of its divisors is an integer number (133215496).

Almost surely, 2^266430991 is an apocalyptic number.

266430991 is a deficient number, since it is larger than the sum of its proper divisors (1).

266430991 is an equidigital number, since it uses as much as digits as its factorization.

266430991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 266430991 is about 16322.7139593880. The cubic root of 266430991 is about 643.4699152204.

The spelling of 266430991 in words is "two hundred sixty-six million, four hundred thirty thousand, nine hundred ninety-one".