21525010 has 48 divisors (see below), whose sum is σ = 43757784. Its totient is φ = 7577856.

The previous prime is 21525001. The next prime is 21525017. The reversal of 21525010 is 1052512.

21525010 = T₂₂₀ + T₂₂₁ + ... + T₅₁₈.

It can be written as a sum of positive squares in 4 ways, for example, as 6056521 + 15468489 = 2461^2 + 3933^2 .

It is a plaindrome in base 9.

It is a zygodrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (21525017) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68614 + ... + 68926.

Almost surely, 2^21525010 is an apocalyptic number.

21525010 is an abundant number, since it is smaller than the sum of its proper divisors (22232774).

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

21525010 is a wasteful number, since it uses less digits than its factorization.

21525010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379 (or 356 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 21525010 is about 4639.5053615660. The cubic root of 21525010 is about 278.1726667449.

Adding to 21525010 its reverse (1052512), we get a palindrome (22577522).

The spelling of 21525010 in words is "twenty-one million, five hundred twenty-five thousand, ten".