221536525 has 12 divisors (see below), whose sum is σ = 313949152. Its totient is φ = 151910640.

The previous prime is 221536517. The next prime is 221536541. The reversal of 221536525 is 525635122.

It is a happy number.

It is not a de Polignac number, because 221536525 - 2³ = 221536517 is a prime.

It is a Duffinian number.

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, 632787 + ... + 633136.

Almost surely, 2^221536525 is an apocalyptic number.

221536525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221536525 is a deficient number, since it is larger than the sum of its proper divisors (92412627).

221536525 is a wasteful number, since it uses less digits than its factorization.

221536525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1265940 (or 1265935 counting only the distinct ones).

The product of its digits is 18000, while the sum is 31.

The square root of 221536525 is about 14884.1030969286. The cubic root of 221536525 is about 605.0832251239.

The spelling of 221536525 in words is "two hundred twenty-one million, five hundred thirty-six thousand, five hundred twenty-five".