21796380 has 108 divisors (see below), whose sum is σ = 70401240. Its totient is φ = 5457408.

The previous prime is 21796351. The next prime is 21796393. The reversal of 21796380 is 8369712.

21796380 is a `hidden beast` number, since 2 + 17 + 9 + 638 + 0 = 666.

It is a super-2 number, since 2×21796380² = 950164362208800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 51811 + ... + 52229.

Almost surely, 2^21796380 is an apocalyptic number.

21796380 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 21796380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35200620).

21796380 is an abundant number, since it is smaller than the sum of its proper divisors (48604860).

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

21796380 is a wasteful number, since it uses less digits than its factorization.

21796380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468 (or 446 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21796380 is about 4668.6593364691. The cubic root of 21796380 is about 279.3367806522.

The spelling of 21796380 in words is "twenty-one million, seven hundred ninety-six thousand, three hundred eighty".