21240886 has 16 divisors (see below), whose sum is σ = 32886720. Its totient is φ = 10281600.

The previous prime is 21240881. The next prime is 21240887. The reversal of 21240886 is 68804212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240881) 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, 17086 + ... + 18286.

It is an arithmetic number, because the mean of its divisors is an integer number (2055420).

Almost surely, 2^21240886 is an apocalyptic number.

21240886 is a deficient number, since it is larger than the sum of its proper divisors (11645834).

21240886 is a wasteful number, since it uses less digits than its factorization.

21240886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1479.

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 21240886 is about 4608.7835705314. The cubic root of 21240886 is about 276.9433083945.

The spelling of 21240886 in words is "twenty-one million, two hundred forty thousand, eight hundred eighty-six".