21543622 has 4 divisors (see below), whose sum is σ = 32315436. Its totient is φ = 10771810.

The previous prime is 21543619. The next prime is 21543653. The reversal of 21543622 is 22634512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5385904 + ... + 5385907.

It is an arithmetic number, because the mean of its divisors is an integer number (8078859).

Almost surely, 2^21543622 is an apocalyptic number.

21543622 is a deficient number, since it is larger than the sum of its proper divisors (10771814).

21543622 is a wasteful number, since it uses less digits than its factorization.

21543622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10771813.

The product of its digits is 2880, while the sum is 25.

The square root of 21543622 is about 4641.5107454362. The cubic root of 21543622 is about 278.2528193698.

It can be divided in two parts, 2154 and 3622, that added together give a square (5776 = 76²).

The spelling of 21543622 in words is "twenty-one million, five hundred forty-three thousand, six hundred twenty-two".