21819608 has 8 divisors (see below), whose sum is σ = 40911780. Its totient is φ = 10909800.

The previous prime is 21819601. The next prime is 21819643. The reversal of 21819608 is 80691812.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21819601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1363718 + ... + 1363733.

Almost surely, 2^21819608 is an apocalyptic number.

It is an amenable number.

21819608 is a deficient number, since it is larger than the sum of its proper divisors (19092172).

21819608 is a wasteful number, since it uses less digits than its factorization.

21819608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2727457 (or 2727453 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 21819608 is about 4671.1463261174. The cubic root of 21819608 is about 279.4359734423.

The spelling of 21819608 in words is "twenty-one million, eight hundred nineteen thousand, six hundred eight".