213221525 has 24 divisors (see below), whose sum is σ = 295481088. Its totient is φ = 151280000.

The previous prime is 213221507. The next prime is 213221527. The reversal of 213221525 is 525122312.

It is not a de Polignac number, because 213221525 - 2¹⁶ = 213155989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213221525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213221527) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1820 + ... + 20730.

It is an arithmetic number, because the mean of its divisors is an integer number (12311712).

Almost surely, 2^213221525 is an apocalyptic number.

213221525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

213221525 is a deficient number, since it is larger than the sum of its proper divisors (82259563).

213221525 is a wasteful number, since it uses less digits than its factorization.

213221525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18973 (or 18968 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 213221525 is about 14602.1068685310. The cubic root of 213221525 is about 597.4162274667.

Adding to 213221525 its reverse (525122312), we get a palindrome (738343837).

The spelling of 213221525 in words is "two hundred thirteen million, two hundred twenty-one thousand, five hundred twenty-five".