21173376 has 64 divisors (see below), whose sum is σ = 64284480. Its totient is φ = 6048768.

The previous prime is 21173357. The next prime is 21173377. The reversal of 21173376 is 67337112.

It is a tau number, because it is divible by the number of its divisors (64).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21173377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1251 + ... + 6626.

It is an arithmetic number, because the mean of its divisors is an integer number (1004445).

Almost surely, 2^21173376 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 21173376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32142240).

21173376 is an abundant number, since it is smaller than the sum of its proper divisors (43111104).

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

21173376 is an equidigital number, since it uses as much as digits as its factorization.

21173376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7901 (or 7889 counting only the distinct ones).

The product of its digits is 5292, while the sum is 30.

The square root of 21173376 is about 4601.4536833483. The cubic root of 21173376 is about 276.6495936304.

The spelling of 21173376 in words is "twenty-one million, one hundred seventy-three thousand, three hundred seventy-six".