21402103 has 2 divisors, whose sum is σ = 21402104. Its totient is φ = 21402102.

The previous prime is 21402091. The next prime is 21402107. The reversal of 21402103 is 30120412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21402103 - 2²¹ = 19304951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21402107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701051 + 10701052.

It is an arithmetic number, because the mean of its divisors is an integer number (10701052).

Almost surely, 2^21402103 is an apocalyptic number.

21402103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21402103 is an equidigital number, since it uses as much as digits as its factorization.

21402103 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21402103 is about 4626.2406984505. The cubic root of 21402103 is about 277.6422039870.

Adding to 21402103 its reverse (30120412), we get a palindrome (51522515).

The spelling of 21402103 in words is "twenty-one million, four hundred two thousand, one hundred three".