21525122 has 4 divisors (see below), whose sum is σ = 32287686. Its totient is φ = 10762560.

The previous prime is 21525121. The next prime is 21525139. The reversal of 21525122 is 22152512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21446161 + 78961 = 4631^2 + 281^2 .

It is a super-2 number, since 2×21525122² = 926661754229768, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21525094 and 21525103.

It is not an unprimeable number, because it can be changed into a prime (21525121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5381279 + ... + 5381282.

Almost surely, 2^21525122 is an apocalyptic number.

21525122 is a deficient number, since it is larger than the sum of its proper divisors (10762564).

21525122 is a wasteful number, since it uses less digits than its factorization.

21525122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10762563.

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

The square root of 21525122 is about 4639.5174318026. The cubic root of 21525122 is about 278.1731492113.

Adding to 21525122 its reverse (22152512), we get a palindrome (43677634).

The spelling of 21525122 in words is "twenty-one million, five hundred twenty-five thousand, one hundred twenty-two".