21980353 has 4 divisors (see below), whose sum is σ = 22491568. Its totient is φ = 21469140.

The previous prime is 21980339. The next prime is 21980363. The reversal of 21980353 is 35308912.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21980353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21980323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255543 + ... + 255628.

It is an arithmetic number, because the mean of its divisors is an integer number (5622892).

Almost surely, 2^21980353 is an apocalyptic number.

It is an amenable number.

21980353 is a deficient number, since it is larger than the sum of its proper divisors (511215).

21980353 is an equidigital number, since it uses as much as digits as its factorization.

21980353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511214.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 21980353 is about 4688.3209147839. The cubic root of 21980353 is about 280.1204966068.

The spelling of 21980353 in words is "twenty-one million, nine hundred eighty thousand, three hundred fifty-three".