21136460 has 12 divisors (see below), whose sum is σ = 44386608. Its totient is φ = 8454576.

The previous prime is 21136441. The next prime is 21136463. The reversal of 21136460 is 6463112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21136463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 528392 + ... + 528431.

It is an arithmetic number, because the mean of its divisors is an integer number (3698884).

Almost surely, 2^21136460 is an apocalyptic number.

21136460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21136460 is an abundant number, since it is smaller than the sum of its proper divisors (23250148).

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

21136460 is a wasteful number, since it uses less digits than its factorization.

21136460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056832 (or 1056830 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21136460 is about 4597.4405923296. The cubic root of 21136460 is about 276.4887196233.

Adding to 21136460 its reverse (6463112), we get a palindrome (27599572).

The spelling of 21136460 in words is "twenty-one million, one hundred thirty-six thousand, four hundred sixty".