21748886 has 4 divisors (see below), whose sum is σ = 32623332. Its totient is φ = 10874442.

The previous prime is 21748871. The next prime is 21748889. The reversal of 21748886 is 68884712.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21748889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5437220 + ... + 5437223.

It is an arithmetic number, because the mean of its divisors is an integer number (8155833).

Almost surely, 2^21748886 is an apocalyptic number.

21748886 is a deficient number, since it is larger than the sum of its proper divisors (10874446).

21748886 is a wasteful number, since it uses less digits than its factorization.

21748886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10874445.

The product of its digits is 172032, while the sum is 44.

The square root of 21748886 is about 4663.5700916787. The cubic root of 21748886 is about 279.1337428265.

The spelling of 21748886 in words is "twenty-one million, seven hundred forty-eight thousand, eight hundred eighty-six".