21563468 has 24 divisors (see below), whose sum is σ = 38837568. Its totient is φ = 10470096.

The previous prime is 21563467. The next prime is 21563471. The reversal of 21563468 is 86436512.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21563467) 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, 48455 + ... + 48897.

It is an arithmetic number, because the mean of its divisors is an integer number (1618232).

Almost surely, 2^21563468 is an apocalyptic number.

It is an amenable number.

21563468 is a deficient number, since it is larger than the sum of its proper divisors (17274100).

21563468 is a wasteful number, since it uses less digits than its factorization.

21563468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 773 (or 771 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 21563468 is about 4643.6481348181. The cubic root of 21563468 is about 278.3382353789.

The spelling of 21563468 in words is "twenty-one million, five hundred sixty-three thousand, four hundred sixty-eight".