21150525 has 48 divisors (see below), whose sum is σ = 39426048. Its totient is φ = 9912000.

The previous prime is 21150523. The next prime is 21150607. The reversal of 21150525 is 52505112.

It is not a de Polignac number, because 21150525 - 2¹ = 21150523 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150523) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25162 + ... + 25988.

It is an arithmetic number, because the mean of its divisors is an integer number (821376).

Almost surely, 2^21150525 is an apocalyptic number.

21150525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21150525 is a deficient number, since it is larger than the sum of its proper divisors (18275523).

21150525 is a wasteful number, since it uses less digits than its factorization.

21150525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882 (or 877 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 21150525 is about 4598.9699933790. The cubic root of 21150525 is about 276.5500347090.

Adding to 21150525 its reverse (52505112), we get a palindrome (73655637).

The spelling of 21150525 in words is "twenty-one million, one hundred fifty thousand, five hundred twenty-five".