21430403 has 2 divisors, whose sum is σ = 21430404. Its totient is φ = 21430402.

The previous prime is 21430379. The next prime is 21430433. The reversal of 21430403 is 30403412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21430403 - 2⁸ = 21430147 is a prime.

It is a super-3 number, since 3×21430403³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21430433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715201 + 10715202.

It is an arithmetic number, because the mean of its divisors is an integer number (10715202).

Almost surely, 2^21430403 is an apocalyptic number.

21430403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430403 is an equidigital number, since it uses as much as digits as its factorization.

21430403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21430403 is about 4629.2983269606. The cubic root of 21430403 is about 277.7645255130.

Adding to 21430403 its reverse (30403412), we get a palindrome (51833815).

The spelling of 21430403 in words is "twenty-one million, four hundred thirty thousand, four hundred three".