21563274 has 16 divisors (see below), whose sum is σ = 43255008. Its totient is φ = 7166352.

The previous prime is 21563273. The next prime is 21563303. The reversal of 21563274 is 47236512.

It is not an unprimeable number, because it can be changed into a prime (21563273) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3097 + ... + 7260.

It is an arithmetic number, because the mean of its divisors is an integer number (2703438).

Almost surely, 2^21563274 is an apocalyptic number.

21563274 is an abundant number, since it is smaller than the sum of its proper divisors (21691734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21563274 is a wasteful number, since it uses less digits than its factorization.

21563274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10709.

The product of its digits is 10080, while the sum is 30.

The square root of 21563274 is about 4643.6272460222. The cubic root of 21563274 is about 278.3374006681.

Adding to 21563274 its reverse (47236512), we get a palindrome (68799786).

The spelling of 21563274 in words is "twenty-one million, five hundred sixty-three thousand, two hundred seventy-four".