21180522 has 32 divisors (see below), whose sum is σ = 46422720. Its totient is φ = 6389120.

The previous prime is 21180491. The next prime is 21180529. The reversal of 21180522 is 22508112.

It is a happy number.

It is a super-2 number, since 2×21180522² = 897229024384968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21180529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17158 + ... + 18350.

It is an arithmetic number, because the mean of its divisors is an integer number (1450710).

Almost surely, 2^21180522 is an apocalyptic number.

21180522 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21180522 is an abundant number, since it is smaller than the sum of its proper divisors (25242198).

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

21180522 is a wasteful number, since it uses less digits than its factorization.

21180522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1478.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 21180522 is about 4602.2301115872. The cubic root of 21180522 is about 276.6807131463.

Adding to 21180522 its reverse (22508112), we get a palindrome (43688634).

The spelling of 21180522 in words is "twenty-one million, one hundred eighty thousand, five hundred twenty-two".