21167380 has 48 divisors (see below), whose sum is σ = 50697360. Its totient is φ = 7354368.

The previous prime is 21167359. The next prime is 21167401. The reversal of 21167380 is 8376112.

It is an interprime number because it is at equal distance from previous prime (21167359) and next prime (21167401).

It can be written as a sum of positive squares in 8 ways, for example, as 2883204 + 18284176 = 1698^2 + 4276^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2026 + ... + 6814.

It is an arithmetic number, because the mean of its divisors is an integer number (1056195).

Almost surely, 2^21167380 is an apocalyptic number.

21167380 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 21167380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25348680).

21167380 is an abundant number, since it is smaller than the sum of its proper divisors (29529980).

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

21167380 is a wasteful number, since it uses less digits than its factorization.

21167380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4828 (or 4826 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21167380 is about 4600.8021039814. The cubic root of 21167380 is about 276.6234767503.

The spelling of 21167380 in words is "twenty-one million, one hundred sixty-seven thousand, three hundred eighty".