21679488 has 192 divisors, whose sum is σ = 70171920. Its totient is φ = 6635520.

The previous prime is 21679477. The next prime is 21679561. The reversal of 21679488 is 88497612.

21679488 is a `hidden beast` number, since 2 + 167 + 9 + 488 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

Its product of digits (193536) is a multiple of the sum of its prime divisors (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 528748 + ... + 528788.

Almost surely, 2^21679488 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21679488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35085960).

21679488 is an abundant number, since it is smaller than the sum of its proper divisors (48492432).

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

21679488 is an equidigital number, since it uses as much as digits as its factorization.

21679488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 63 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 21679488 is about 4656.1237096967. The cubic root of 21679488 is about 278.8365327545.

The spelling of 21679488 in words is "twenty-one million, six hundred seventy-nine thousand, four hundred eighty-eight".