21127530 has 16 divisors (see below), whose sum is σ = 50706144. Its totient is φ = 5634000.

The previous prime is 21127507. The next prime is 21127537. The reversal of 21127530 is 3572112.

It is a junction number, because it is equal to n+sod(n) for n = 21127497 and 21127506.

It is not an unprimeable number, because it can be changed into a prime (21127537) 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, 352096 + ... + 352155.

It is an arithmetic number, because the mean of its divisors is an integer number (3169134).

Almost surely, 2^21127530 is an apocalyptic number.

21127530 is an abundant number, since it is smaller than the sum of its proper divisors (29578614).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21127530 is a wasteful number, since it uses less digits than its factorization.

21127530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704261.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21127530 is about 4596.4692971889. The cubic root of 21127530 is about 276.4497759833.

Adding to 21127530 its reverse (3572112), we get a palindrome (24699642).

The spelling of 21127530 in words is "twenty-one million, one hundred twenty-seven thousand, five hundred thirty".