21179028 has 48 divisors (see below), whose sum is σ = 53688320. Its totient is φ = 6459264.

The previous prime is 21179023. The next prime is 21179033. The reversal of 21179028 is 82097112.

It is an interprime number because it is at equal distance from previous prime (21179023) and next prime (21179033).

It is a junction number, because it is equal to n+sod(n) for n = 21178986 and 21179004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21179023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19278 + ... + 20346.

Almost surely, 2^21179028 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 21179028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26844160).

21179028 is an abundant number, since it is smaller than the sum of its proper divisors (32509292).

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

21179028 is a wasteful number, since it uses less digits than its factorization.

21179028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216 (or 1214 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 21179028 is about 4602.0677961108. The cubic root of 21179028 is about 276.6742076298.

The spelling of 21179028 in words is "twenty-one million, one hundred seventy-nine thousand, twenty-eight".