213856749 has 24 divisors (see below), whose sum is σ = 316599192. Its totient is φ = 139052160.

The previous prime is 213856739. The next prime is 213856793. The reversal of 213856749 is 947658312.

It can be written as a sum of positive squares in 4 ways, for example, as 5978025 + 207878724 = 2445^2 + 14418^2 .

It is not a de Polignac number, because 213856749 - 2⁵ = 213856717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213856739) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85099 + ... + 87575.

It is an arithmetic number, because the mean of its divisors is an integer number (13191633).

Almost surely, 2^213856749 is an apocalyptic number.

It is an amenable number.

213856749 is a deficient number, since it is larger than the sum of its proper divisors (102742443).

213856749 is a wasteful number, since it uses less digits than its factorization.

213856749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2717 (or 2714 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 213856749 is about 14623.8418002931. The cubic root of 213856749 is about 598.0089082315.

The spelling of 213856749 in words is "two hundred thirteen million, eight hundred fifty-six thousand, seven hundred forty-nine".