21967380 has 36 divisors (see below), whose sum is σ = 66634932. Its totient is φ = 5857920.

The previous prime is 21967343. The next prime is 21967397. The reversal of 21967380 is 8376912.

21967380 is a `hidden beast` number, since 219 + 67 + 380 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6380676 + 15586704 = 2526^2 + 3948^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a plaindrome in base 11.

It is a zygodrome in base 11.

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 11 ways as a sum of consecutive naturals, for example, 60841 + ... + 61200.

Almost surely, 2^21967380 is an apocalyptic number.

21967380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21967380 is an abundant number, since it is smaller than the sum of its proper divisors (44667552).

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

21967380 is a wasteful number, since it uses less digits than its factorization.

21967380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122056 (or 122051 counting only the distinct ones).

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

The square root of 21967380 is about 4686.9371662099. The cubic root of 21967380 is about 280.0653758910.

The spelling of 21967380 in words is "twenty-one million, nine hundred sixty-seven thousand, three hundred eighty".