213211705 has 32 divisors (see below), whose sum is σ = 310915584. Its totient is φ = 137020416.

The previous prime is 213211703. The next prime is 213211709. The reversal of 213211705 is 507112312.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 213211705 - 2¹ = 213211703 is a prime.

It is a super-2 number, since 2×213211705² = 90918462298014050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (213211703) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 173724 + ... + 174946.

It is an arithmetic number, because the mean of its divisors is an integer number (9716112).

Almost surely, 2^213211705 is an apocalyptic number.

It is an amenable number.

213211705 is a deficient number, since it is larger than the sum of its proper divisors (97703879).

213211705 is a wasteful number, since it uses less digits than its factorization.

213211705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1545.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 213211705 is about 14601.7706118128. The cubic root of 213211705 is about 597.4070559139.

The spelling of 213211705 in words is "two hundred thirteen million, two hundred eleven thousand, seven hundred five".