21980403 has 10 divisors (see below), whose sum is σ = 32835044. Its totient is φ = 14653548.

The previous prime is 21980401. The next prime is 21980411. The reversal of 21980403 is 30408912.

It is not a de Polignac number, because 21980403 - 2¹ = 21980401 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21980401) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 135601 + ... + 135762.

Almost surely, 2^21980403 is an apocalyptic number.

21980403 is a deficient number, since it is larger than the sum of its proper divisors (10854641).

21980403 is an equidigital number, since it uses as much as digits as its factorization.

21980403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271375 (or 271366 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21980403 is about 4688.3262471803. The cubic root of 21980403 is about 280.1207090089.

The spelling of 21980403 in words is "twenty-one million, nine hundred eighty thousand, four hundred three".