21868156 has 12 divisors (see below), whose sum is σ = 38321640. Its totient is φ = 10919120.

The previous prime is 21868141. The next prime is 21868169. The reversal of 21868156 is 65186812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46 + ... + 6613.

It is an arithmetic number, because the mean of its divisors is an integer number (3193470).

Almost surely, 2^21868156 is an apocalyptic number.

It is an amenable number.

21868156 is a deficient number, since it is larger than the sum of its proper divisors (16453484).

21868156 is a wasteful number, since it uses less digits than its factorization.

21868156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7484 (or 7482 counting only the distinct ones).

The product of its digits is 23040, while the sum is 37.

The square root of 21868156 is about 4676.3400218547. The cubic root of 21868156 is about 279.6430655938.

The spelling of 21868156 in words is "twenty-one million, eight hundred sixty-eight thousand, one hundred fifty-six".