213400644 has 24 divisors (see below), whose sum is σ = 500467968. Its totient is φ = 70771680.

The previous prime is 213400639. The next prime is 213400651. The reversal of 213400644 is 446004312.

It is a super-2 number, since 2×213400644² = 91079669719229472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42772 + ... + 47499.

It is an arithmetic number, because the mean of its divisors is an integer number (20852832).

Almost surely, 2^213400644 is an apocalyptic number.

It is an amenable number.

213400644 is an abundant number, since it is smaller than the sum of its proper divisors (287067324).

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

213400644 is a wasteful number, since it uses less digits than its factorization.

213400644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90475 (or 90473 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 213400644 is about 14608.2389082326. The cubic root of 213400644 is about 597.5834692538.

Adding to 213400644 its reverse (446004312), we get a palindrome (659404956).

The spelling of 213400644 in words is "two hundred thirteen million, four hundred thousand, six hundred forty-four".