21220403 has 12 divisors (see below), whose sum is σ = 22796592. Its totient is φ = 19747200.

The previous prime is 21220393. The next prime is 21220417. The reversal of 21220403 is 30402212.

It is not a de Polignac number, because 21220403 - 2¹⁰ = 21219379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21220103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28826 + ... + 29552.

It is an arithmetic number, because the mean of its divisors is an integer number (1899716).

Almost surely, 2^21220403 is an apocalyptic number.

21220403 is a deficient number, since it is larger than the sum of its proper divisors (1576189).

21220403 is a wasteful number, since it uses less digits than its factorization.

21220403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862 (or 845 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21220403 is about 4606.5608646799. The cubic root of 21220403 is about 276.8542591559.

Adding to 21220403 its reverse (30402212), we get a palindrome (51622615).

The spelling of 21220403 in words is "twenty-one million, two hundred twenty thousand, four hundred three".