21413403 has 24 divisors (see below), whose sum is σ = 34996416. Its totient is φ = 12976200.

The previous prime is 21413393. The next prime is 21413423. The reversal of 21413403 is 30431412.

It is not a de Polignac number, because 21413403 - 2¹⁸ = 21151259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21413423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1333 + ... + 6678.

It is an arithmetic number, because the mean of its divisors is an integer number (1458184).

Almost surely, 2^21413403 is an apocalyptic number.

21413403 is a deficient number, since it is larger than the sum of its proper divisors (13583013).

21413403 is an equidigital number, since it uses as much as digits as its factorization.

21413403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8037 (or 8025 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21413403 is about 4627.4618312851. The cubic root of 21413403 is about 277.6910590755.

Adding to 21413403 its reverse (30431412), we get a palindrome (51844815).

Subtracting 21413403 from its reverse (30431412), we obtain a square (9018009 = 3003²).

The spelling of 21413403 in words is "twenty-one million, four hundred thirteen thousand, four hundred three".