21197376 has 168 divisors, whose sum is σ = 66568320. Its totient is φ = 6676992.

The previous prime is 21197357. The next prime is 21197377. The reversal of 21197376 is 67379112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (15876) is a multiple of the sum of its prime divisors (81).

It is a self number, because there is not a number n which added to its sum of digits gives 21197376.

It is not an unprimeable number, because it can be changed into a prime (21197377) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 450985 + ... + 451031.

It is an arithmetic number, because the mean of its divisors is an integer number (396240).

Almost surely, 2^21197376 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 21197376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33284160).

21197376 is an abundant number, since it is smaller than the sum of its proper divisors (45370944).

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

21197376 is an equidigital number, since it uses as much as digits as its factorization.

21197376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 81 counting only the distinct ones).

The product of its digits is 15876, while the sum is 36.

The square root of 21197376 is about 4604.0608162795. The cubic root of 21197376 is about 276.7540815050.

It can be divided in two parts, 2 and 1197376, that added together give a triangular number (1197378 = T₁₅₄₇).

The spelling of 21197376 in words is "twenty-one million, one hundred ninety-seven thousand, three hundred seventy-six".