21179080 has 64 divisors (see below), whose sum is σ = 51836400. Its totient is φ = 7787520.

The previous prime is 21179071. The next prime is 21179089. The reversal of 21179080 is 8097112.

It is an interprime number because it is at equal distance from previous prime (21179071) and next prime (21179089).

It can be written as a sum of positive squares in 8 ways, for example, as 367236 + 20811844 = 606^2 + 4562^2 .

It is not an unprimeable number, because it can be changed into a prime (21179089) 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, 87760 + ... + 88000.

Almost surely, 2^21179080 is an apocalyptic number.

21179080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21179080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25918200).

21179080 is an abundant number, since it is smaller than the sum of its proper divisors (30657320).

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

21179080 is a wasteful number, since it uses less digits than its factorization.

21179080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 21179080 is about 4602.0734457416. The cubic root of 21179080 is about 276.6744340652.

It can be divided in two parts, 21 and 179080, that added together give a triangular number (179101 = T₅₉₈).

The spelling of 21179080 in words is "twenty-one million, one hundred seventy-nine thousand, eighty".