213738491 has 2 divisors, whose sum is σ = 213738492. Its totient is φ = 213738490.

The previous prime is 213738487. The next prime is 213738527. The reversal of 213738491 is 194837312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213738491 - 2² = 213738487 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (213738401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106869245 + 106869246.

It is an arithmetic number, because the mean of its divisors is an integer number (106869246).

Almost surely, 2^213738491 is an apocalyptic number.

213738491 is a deficient number, since it is larger than the sum of its proper divisors (1).

213738491 is an equidigital number, since it uses as much as digits as its factorization.

213738491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 213738491 is about 14619.7979124200. The cubic root of 213738491 is about 597.8986593893.

The spelling of 213738491 in words is "two hundred thirteen million, seven hundred thirty-eight thousand, four hundred ninety-one".