21144423434 has 16 divisors (see below), whose sum is σ = 33113057472. Its totient is φ = 10107222048.

The previous prime is 21144423413. The next prime is 21144423499. The reversal of 21144423434 is 43432444112.

It is a self number, because there is not a number n which added to its sum of digits gives 21144423434.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32144 + ... + 208139.

It is an arithmetic number, because the mean of its divisors is an integer number (2069566092).

Almost surely, 2^21144423434 is an apocalyptic number.

21144423434 is a deficient number, since it is larger than the sum of its proper divisors (11968634038).

21144423434 is a wasteful number, since it uses less digits than its factorization.

21144423434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242221.

The product of its digits is 36864, while the sum is 32.

Adding to 21144423434 its reverse (43432444112), we get a palindrome (64576867546).

The spelling of 21144423434 in words is "twenty-one billion, one hundred forty-four million, four hundred twenty-three thousand, four hundred thirty-four".