213400521 has 8 divisors (see below), whose sum is σ = 316148960. Its totient is φ = 142266996.

The previous prime is 213400493. The next prime is 213400543. The reversal of 213400521 is 125004312.

213400521 is a `hidden beast` number, since 213 + 400 + 52 + 1 = 666.

It is not a de Polignac number, because 213400521 - 2²³ = 205011913 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213400494 and 213400503.

It is not an unprimeable number, because it can be changed into a prime (213402521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3951835 + ... + 3951888.

It is an arithmetic number, because the mean of its divisors is an integer number (39518620).

Almost surely, 2^213400521 is an apocalyptic number.

It is an amenable number.

213400521 is a deficient number, since it is larger than the sum of its proper divisors (102748439).

213400521 is an equidigital number, since it uses as much as digits as its factorization.

213400521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7903732 (or 7903726 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 213400521 is about 14608.2346982789. The cubic root of 213400521 is about 597.5833544419.

Adding to 213400521 its reverse (125004312), we get a palindrome (338404833).

The spelling of 213400521 in words is "two hundred thirteen million, four hundred thousand, five hundred twenty-one".