21628694 has 12 divisors (see below), whose sum is σ = 33916596. Its totient is φ = 10343652.

The previous prime is 21628681. The next prime is 21628697. The reversal of 21628694 is 49682612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21628697) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9164 + ... + 11279.

It is an arithmetic number, because the mean of its divisors is an integer number (2826383).

Almost surely, 2^21628694 is an apocalyptic number.

21628694 is a deficient number, since it is larger than the sum of its proper divisors (12287902).

21628694 is a wasteful number, since it uses less digits than its factorization.

21628694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20491 (or 20468 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 21628694 is about 4650.6659738149. The cubic root of 21628694 is about 278.6185955887.

It can be divided in two parts, 21628 and 694, that added together give a palindrome (22322).

The spelling of 21628694 in words is "twenty-one million, six hundred twenty-eight thousand, six hundred ninety-four".