21520060 has 12 divisors (see below), whose sum is σ = 45192168. Its totient is φ = 8608016.

The previous prime is 21520021. The next prime is 21520061. The reversal of 21520060 is 6002512.

It is a happy number.

It is a super-2 number, since 2×21520060² = 926225964807200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 537982 + ... + 538021.

It is an arithmetic number, because the mean of its divisors is an integer number (3766014).

Almost surely, 2^21520060 is an apocalyptic number.

21520060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21520060 is an abundant number, since it is smaller than the sum of its proper divisors (23672108).

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

21520060 is a wasteful number, since it uses less digits than its factorization.

21520060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076012 (or 1076010 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21520060 is about 4638.9718688520. The cubic root of 21520060 is about 278.1513417798.

Adding to 21520060 its reverse (6002512), we get a palindrome (27522572).

The spelling of 21520060 in words is "twenty-one million, five hundred twenty thousand, sixty".