21252707 has 8 divisors (see below), whose sum is σ = 24854016. Its totient is φ = 17792712.

The previous prime is 21252691. The next prime is 21252727. The reversal of 21252707 is 70725212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21252707 - 2⁴ = 21252691 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21252727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35003 + ... + 35604.

It is an arithmetic number, because the mean of its divisors is an integer number (3106752).

Almost surely, 2^21252707 is an apocalyptic number.

21252707 is a deficient number, since it is larger than the sum of its proper divisors (3601309).

21252707 is an equidigital number, since it uses as much as digits as its factorization.

21252707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70657.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 21252707 is about 4610.0658346709. The cubic root of 21252707 is about 276.9946737932.

Adding to 21252707 its reverse (70725212), we get a palindrome (91977919).

The spelling of 21252707 in words is "twenty-one million, two hundred fifty-two thousand, seven hundred seven".