21522512 has 30 divisors (see below), whose sum is σ = 45839514. Its totient is φ = 9782080.

The previous prime is 21522511. The next prime is 21522521.

It is a happy number.

21522512 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 14318656 + 7203856 = 3784^2 + 2684^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3623 + ... + 7494.

Almost surely, 2^21522512 is an apocalyptic number.

21522512 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21522512 is an abundant number, since it is smaller than the sum of its proper divisors (24317002).

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

21522512 is a wasteful number, since it uses less digits than its factorization.

21522512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11147 (or 11130 counting only the distinct ones).

The product of its digits is 400, while the sum is 20.

The square root of 21522512 is about 4639.2361440220. The cubic root of 21522512 is about 278.1619055853.

It can be divided in two parts, 2152 and 2512, that added together give a palindrome (4664).

The spelling of 21522512 in words is "twenty-one million, five hundred twenty-two thousand, five hundred twelve".