21537226 has 8 divisors (see below), whose sum is σ = 32328000. Its totient is φ = 10761228.

The previous prime is 21537179. The next prime is 21537251. The reversal of 21537226 is 62273512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21537194 and 21537203.

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, 1305 + ... + 6691.

It is an arithmetic number, because the mean of its divisors is an integer number (4041000).

Almost surely, 2^21537226 is an apocalyptic number.

21537226 is a deficient number, since it is larger than the sum of its proper divisors (10790774).

21537226 is a wasteful number, since it uses less digits than its factorization.

21537226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7388.

The product of its digits is 5040, while the sum is 28.

The square root of 21537226 is about 4640.8216944847. The cubic root of 21537226 is about 278.2252801878.

The spelling of 21537226 in words is "twenty-one million, five hundred thirty-seven thousand, two hundred twenty-six".