21142886 has 16 divisors (see below), whose sum is σ = 32432400. Its totient is φ = 10334208.

The previous prime is 21142871. The next prime is 21142889. The reversal of 21142886 is 68824112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142889) 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, 27110 + ... + 27878.

It is an arithmetic number, because the mean of its divisors is an integer number (2027025).

Almost surely, 2^21142886 is an apocalyptic number.

21142886 is a deficient number, since it is larger than the sum of its proper divisors (11289514).

21142886 is a wasteful number, since it uses less digits than its factorization.

21142886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063.

The product of its digits is 6144, while the sum is 32.

The square root of 21142886 is about 4598.1394063251. The cubic root of 21142886 is about 276.5167365584.

Adding to 21142886 its reverse (68824112), we get a palindrome (89966998).

The spelling of 21142886 in words is "twenty-one million, one hundred forty-two thousand, eight hundred eighty-six".