213454991 has 2 divisors, whose sum is σ = 213454992. Its totient is φ = 213454990.

The previous prime is 213454981. The next prime is 213455023. The reversal of 213454991 is 199454312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213454991 - 2²² = 209260687 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213454981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106727495 + 106727496.

It is an arithmetic number, because the mean of its divisors is an integer number (106727496).

Almost surely, 2^213454991 is an apocalyptic number.

213454991 is a deficient number, since it is larger than the sum of its proper divisors (1).

213454991 is an equidigital number, since it uses as much as digits as its factorization.

213454991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 38.

The square root of 213454991 is about 14610.0989387478. The cubic root of 213454991 is about 597.6341940495.

The spelling of 213454991 in words is "two hundred thirteen million, four hundred fifty-four thousand, nine hundred ninety-one".