21252710 has 16 divisors (see below), whose sum is σ = 38328336. Its totient is φ = 8484768.

The previous prime is 21252691. The next prime is 21252727. The reversal of 21252710 is 1725212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4397 + ... + 7863.

It is an arithmetic number, because the mean of its divisors is an integer number (2395521).

Almost surely, 2^21252710 is an apocalyptic number.

21252710 is a deficient number, since it is larger than the sum of its proper divisors (17075626).

21252710 is a wasteful number, since it uses less digits than its factorization.

21252710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4087.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 21252710 is about 4610.0661600459. The cubic root of 21252710 is about 276.9946868265.

Adding to 21252710 its reverse (1725212), we get a palindrome (22977922).

The spelling of 21252710 in words is "twenty-one million, two hundred fifty-two thousand, seven hundred ten".