21153404 has 12 divisors (see below), whose sum is σ = 37083144. Its totient is φ = 10558224.

The previous prime is 21153373. The next prime is 21153409. The reversal of 21153404 is 40435112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1862 + ... + 6765.

It is an arithmetic number, because the mean of its divisors is an integer number (3090262).

Almost surely, 2^21153404 is an apocalyptic number.

It is an amenable number.

21153404 is a deficient number, since it is larger than the sum of its proper divisors (15929740).

21153404 is a wasteful number, since it uses less digits than its factorization.

21153404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9244 (or 9242 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21153404 is about 4599.2829875971. The cubic root of 21153404 is about 276.5625820954.

Adding to 21153404 its reverse (40435112), we get a palindrome (61588516).

The spelling of 21153404 in words is "twenty-one million, one hundred fifty-three thousand, four hundred four".