213685949 has 8 divisors (see below), whose sum is σ = 222467160. Its totient is φ = 204998976.

The previous prime is 213685943. The next prime is 213685957. The reversal of 213685949 is 949586312.

It can be written as a sum of positive squares in 4 ways, for example, as 25 + 213685924 = 5^2 + 14618^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 213685949 - 2¹⁶ = 213620413 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213685943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18914 + ... + 28019.

It is an arithmetic number, because the mean of its divisors is an integer number (27808395).

Almost surely, 2^213685949 is an apocalyptic number.

213685949 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

213685949 is a deficient number, since it is larger than the sum of its proper divisors (8781211).

213685949 is a wasteful number, since it uses less digits than its factorization.

213685949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47119.

The product of its digits is 466560, while the sum is 47.

The square root of 213685949 is about 14618.0008551101. Note that the first 3 decimals coincide. The cubic root of 213685949 is about 597.8496628083.

The spelling of 213685949 in words is "two hundred thirteen million, six hundred eighty-five thousand, nine hundred forty-nine".