21539060 has 12 divisors (see below), whose sum is σ = 45232068. Its totient is φ = 8615616.

The previous prime is 21539059. The next prime is 21539101. The reversal of 21539060 is 6093512.

It can be written as a sum of positive squares in 2 ways, for example, as 11641744 + 9897316 = 3412^2 + 3146^2 .

It is a super-2 number, since 2×21539060² = 927862211367200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538457 + ... + 538496.

It is an arithmetic number, because the mean of its divisors is an integer number (3769339).

Almost surely, 2^21539060 is an apocalyptic number.

21539060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21539060 is an abundant number, since it is smaller than the sum of its proper divisors (23693008).

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

21539060 is a wasteful number, since it uses less digits than its factorization.

21539060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076962 (or 1076960 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 21539060 is about 4641.0192845969. The cubic root of 21539060 is about 278.2331773775.

The spelling of 21539060 in words is "twenty-one million, five hundred thirty-nine thousand, sixty".