21286124 has 12 divisors (see below), whose sum is σ = 37283400. Its totient is φ = 10633728.

The previous prime is 21286123. The next prime is 21286129. The reversal of 21286124 is 42168212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21286093 and 21286102.

It is not an unprimeable number, because it can be changed into a prime (21286121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6572 + ... + 9260.

It is an arithmetic number, because the mean of its divisors is an integer number (3106950).

Almost surely, 2^21286124 is an apocalyptic number.

It is an amenable number.

21286124 is a deficient number, since it is larger than the sum of its proper divisors (15997276).

21286124 is a wasteful number, since it uses less digits than its factorization.

21286124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4672 (or 4670 counting only the distinct ones).

The product of its digits is 1536, while the sum is 26.

The square root of 21286124 is about 4613.6887628014. The cubic root of 21286124 is about 277.1397766234.

The spelling of 21286124 in words is "twenty-one million, two hundred eighty-six thousand, one hundred twenty-four".