213221964 has 12 divisors (see below), whose sum is σ = 497517944. Its totient is φ = 71073984.

The previous prime is 213221963. The next prime is 213222013. The reversal of 213221964 is 469122312.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (213221963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8884237 + ... + 8884260.

Almost surely, 2^213221964 is an apocalyptic number.

It is an amenable number.

213221964 is an abundant number, since it is smaller than the sum of its proper divisors (284295980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213221964 is a wasteful number, since it uses less digits than its factorization.

213221964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17768504 (or 17768502 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 213221964 is about 14602.1219006006. The cubic root of 213221964 is about 597.4166374715.

It can be divided in two parts, 213221 and 964, that added together give a triangular number (214185 = T₆₅₄).

The spelling of 213221964 in words is "two hundred thirteen million, two hundred twenty-one thousand, nine hundred sixty-four".