21423611 has 8 divisors (see below), whose sum is σ = 23701248. Its totient is φ = 19201000.

The previous prime is 21423601. The next prime is 21423613. The reversal of 21423611 is 11632412.

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 21423611 - 2¹⁰ = 21422587 is a prime.

It is a super-2 number, since 2×21423611² = 917942216558642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21423613) 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, 12935 + ... + 14496.

It is an arithmetic number, because the mean of its divisors is an integer number (2962656).

Almost surely, 2^21423611 is an apocalyptic number.

21423611 is a deficient number, since it is larger than the sum of its proper divisors (2277637).

21423611 is a wasteful number, since it uses less digits than its factorization.

21423611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27513.

The product of its digits is 288, while the sum is 20.

The square root of 21423611 is about 4628.5646803302. The cubic root of 21423611 is about 277.7351781725.

The spelling of 21423611 in words is "twenty-one million, four hundred twenty-three thousand, six hundred eleven".