213749 has 8 divisors (see below), whose sum is σ = 225720. Its totient is φ = 202176.

The previous prime is 213737. The next prime is 213751. The reversal of 213749 is 947312.

213749 = T₆₂ + T₆₃ + ... + T₁₁₄.

It can be written as a sum of positive squares in 4 ways, for example, as 117649 + 96100 = 343^2 + 310^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213749 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213799) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1907 + ... + 2015.

It is an arithmetic number, because the mean of its divisors is an integer number (28215).

2²¹³⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

213749 is a deficient number, since it is larger than the sum of its proper divisors (11971).

213749 is a wasteful number, since it uses less digits than its factorization.

213749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199.

The product of its digits is 1512, while the sum is 26.

The square root of 213749 is about 462.3299687453. The cubic root of 213749 is about 59.7908458301.

The spelling of 213749 in words is "two hundred thirteen thousand, seven hundred forty-nine".