21240669 has 8 divisors (see below), whose sum is σ = 28429632. Its totient is φ = 14106080.

The previous prime is 21240643. The next prime is 21240683. The reversal of 21240669 is 96604212.

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 21240669 - 2¹² = 21236573 is a prime.

It is a super-2 number, since 2×21240669² = 902332039135122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244669) 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, 12672 + ... + 14249.

It is an arithmetic number, because the mean of its divisors is an integer number (3553704).

Almost surely, 2^21240669 is an apocalyptic number.

It is an amenable number.

21240669 is a deficient number, since it is larger than the sum of its proper divisors (7188963).

21240669 is a wasteful number, since it uses less digits than its factorization.

21240669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27187.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 21240669 is about 4608.7600284675. The cubic root of 21240669 is about 276.9423652935.

The spelling of 21240669 in words is "twenty-one million, two hundred forty thousand, six hundred sixty-nine".