21251069 has 8 divisors (see below), whose sum is σ = 24337728. Its totient is φ = 18177120.

The previous prime is 21251053. The next prime is 21251077. The reversal of 21251069 is 96015212.

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

It is a cyclic number.

It is not a de Polignac number, because 21251069 - 2⁴ = 21251053 is a prime.

It is a super-2 number, since 2×21251069² = 903215867285522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 734 + ... + 6560.

It is an arithmetic number, because the mean of its divisors is an integer number (3042216).

Almost surely, 2^21251069 is an apocalyptic number.

It is an amenable number.

21251069 is a deficient number, since it is larger than the sum of its proper divisors (3086659).

21251069 is an equidigital number, since it uses as much as digits as its factorization.

21251069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6355.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 21251069 is about 4609.8881765180. Note that the first 3 decimals coincide. The cubic root of 21251069 is about 276.9875573831.

The spelling of 21251069 in words is "twenty-one million, two hundred fifty-one thousand, sixty-nine".