149209813 has 2 divisors, whose sum is σ = 149209814. Its totient is φ = 149209812.

The previous prime is 149209811. The next prime is 149209861. The reversal of 149209813 is 318902941.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148791204 + 418609 = 12198^2 + 647^2 .

It is a cyclic number.

It is not a de Polignac number, because 149209813 - 2¹ = 149209811 is a prime.

Together with 149209811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (149209811) 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, 74604906 + 74604907.

It is an arithmetic number, because the mean of its divisors is an integer number (74604907).

Almost surely, 2^149209813 is an apocalyptic number.

It is an amenable number.

149209813 is a deficient number, since it is larger than the sum of its proper divisors (1).

149209813 is an equidigital number, since it uses as much as digits as its factorization.

149209813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 149209813 is about 12215.1468677212. The cubic root of 149209813 is about 530.3946425864.

The spelling of 149209813 in words is "one hundred forty-nine million, two hundred nine thousand, eight hundred thirteen".