213847731 has 12 divisors (see below), whose sum is σ = 309812152. Its totient is φ = 142140096.

The previous prime is 213847723. The next prime is 213847741. The reversal of 213847731 is 137748312.

It is not a de Polignac number, because 213847731 - 2³ = 213847723 is a prime.

It is a super-2 number, since 2×213847731² = 91461704107696722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213847741) 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 11 ways as a sum of consecutive naturals, for example, 32221 + ... + 38286.

Almost surely, 2^213847731 is an apocalyptic number.

213847731 is a deficient number, since it is larger than the sum of its proper divisors (95964421).

213847731 is a wasteful number, since it uses less digits than its factorization.

213847731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70850 (or 70847 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 213847731 is about 14623.5334649325. The cubic root of 213847731 is about 598.0005024175. Note that the first 3 decimals are identical.

The spelling of 213847731 in words is "two hundred thirteen million, eight hundred forty-seven thousand, seven hundred thirty-one".