21403413 has 16 divisors (see below), whose sum is σ = 31785600. Its totient is φ = 14234400.

The previous prime is 21403399. The next prime is 21403433. The reversal of 21403413 is 31430412.

It is a de Polignac number, because none of the positive numbers 2^k-21403413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21403433) 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, 15568 + ... + 16886.

It is an arithmetic number, because the mean of its divisors is an integer number (1986600).

Almost surely, 2^21403413 is an apocalyptic number.

It is an amenable number.

21403413 is a deficient number, since it is larger than the sum of its proper divisors (10382187).

21403413 is a wasteful number, since it uses less digits than its factorization.

21403413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1929 (or 1923 counting only the distinct ones).

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

The square root of 21403413 is about 4626.3822799246. The cubic root of 21403413 is about 277.6478685996.

Adding to 21403413 its reverse (31430412), we get a palindrome (52833825).

The spelling of 21403413 in words is "twenty-one million, four hundred three thousand, four hundred thirteen".