21154430 has 24 divisors (see below), whose sum is σ = 41856696. Its totient is φ = 7692080.

The previous prime is 21154403. The next prime is 21154447. The reversal of 21154430 is 3445112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7532 + ... + 9951.

It is an arithmetic number, because the mean of its divisors is an integer number (1744029).

Almost surely, 2^21154430 is an apocalyptic number.

21154430 is a deficient number, since it is larger than the sum of its proper divisors (20702266).

21154430 is a wasteful number, since it uses less digits than its factorization.

21154430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17512 (or 17501 counting only the distinct ones).

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

The square root of 21154430 is about 4599.3945253696. The cubic root of 21154430 is about 276.5670533792.

Adding to 21154430 its reverse (3445112), we get a palindrome (24599542).

It can be divided in two parts, 21 and 154430, that added together give a palindrome (154451).

The spelling of 21154430 in words is "twenty-one million, one hundred fifty-four thousand, four hundred thirty".