21138060 has 24 divisors (see below), whose sum is σ = 59186736. Its totient is φ = 5636800.

The previous prime is 21138059. The next prime is 21138067. The reversal of 21138060 is 6083112.

It is a plaindrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (21138067) 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, 176091 + ... + 176210.

It is an arithmetic number, because the mean of its divisors is an integer number (2466114).

Almost surely, 2^21138060 is an apocalyptic number.

21138060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21138060 is an abundant number, since it is smaller than the sum of its proper divisors (38048676).

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

21138060 is a wasteful number, since it uses less digits than its factorization.

21138060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352313 (or 352311 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21138060 is about 4597.6145988980. The cubic root of 21138060 is about 276.4956960483.

The spelling of 21138060 in words is "twenty-one million, one hundred thirty-eight thousand, sixty".