21435404 has 6 divisors (see below), whose sum is σ = 37511964. Its totient is φ = 10717700.

The previous prime is 21435391. The next prime is 21435409. The reversal of 21435404 is 40453412.

It is a self number, because there is not a number n which added to its sum of digits gives 21435404.

It is not an unprimeable number, because it can be changed into a prime (21435409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2679422 + ... + 2679429.

It is an arithmetic number, because the mean of its divisors is an integer number (6251994).

Almost surely, 2^21435404 is an apocalyptic number.

It is an amenable number.

21435404 is a deficient number, since it is larger than the sum of its proper divisors (16076560).

21435404 is a wasteful number, since it uses less digits than its factorization.

21435404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5358855 (or 5358853 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 21435404 is about 4629.8384421057. The cubic root of 21435404 is about 277.7861302140.

Adding to 21435404 its reverse (40453412), we get a palindrome (61888816).

The spelling of 21435404 in words is "twenty-one million, four hundred thirty-five thousand, four hundred four".