21425403 has 16 divisors (see below), whose sum is σ = 29675520. Its totient is φ = 13733664.

The previous prime is 21425401. The next prime is 21425413. The reversal of 21425403 is 30452412.

It is not a de Polignac number, because 21425403 - 2¹ = 21425401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21425403.

It is not an unprimeable number, because it can be changed into a prime (21425401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33000 + ... + 33642.

It is an arithmetic number, because the mean of its divisors is an integer number (1854720).

Almost surely, 2^21425403 is an apocalyptic number.

21425403 is a deficient number, since it is larger than the sum of its proper divisors (8250117).

21425403 is a wasteful number, since it uses less digits than its factorization.

21425403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1058.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21425403 is about 4628.7582568114. The cubic root of 21425403 is about 277.7429217716.

Adding to 21425403 its reverse (30452412), we get a palindrome (51877815).

The spelling of 21425403 in words is "twenty-one million, four hundred twenty-five thousand, four hundred three".