211216525 has 12 divisors (see below), whose sum is σ = 282055732. Its totient is φ = 155975040.

The previous prime is 211216507. The next prime is 211216531. The reversal of 211216525 is 525612112.

211216525 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 66564 + 211149961 = 258^2 + 14531^2 .

It is not a de Polignac number, because 211216525 - 2⁵ = 211216493 is a prime.

It is a super-2 number, since 2×211216525² = 89224840866151250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

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 211216525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 324624 + ... + 325273.

Almost surely, 2^211216525 is an apocalyptic number.

211216525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

211216525 is a deficient number, since it is larger than the sum of its proper divisors (70839207).

211216525 is a wasteful number, since it uses less digits than its factorization.

211216525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649920 (or 649915 counting only the distinct ones).

The product of its digits is 1200, while the sum is 25.

The square root of 211216525 is about 14533.2902331165. The cubic root of 211216525 is about 595.5377526652.

Adding to 211216525 its reverse (525612112), we get a palindrome (736828637).

The spelling of 211216525 in words is "two hundred eleven million, two hundred sixteen thousand, five hundred twenty-five".