21423032144 has 10 divisors (see below), whose sum is σ = 41507124810. Its totient is φ = 10711516064.

The previous prime is 21423032123. The next prime is 21423032159. The reversal of 21423032144 is 44123032412.

It can be written as a sum of positive squares in only one way, i.e., 14684592400 + 6738439744 = 121180^2 + 82088^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 669469739 + ... + 669469770.

It is an arithmetic number, because the mean of its divisors is an integer number (4150712481).

Almost surely, 2^21423032144 is an apocalyptic number.

It is an amenable number.

21423032144 is a deficient number, since it is larger than the sum of its proper divisors (20084092666).

21423032144 is a wasteful number, since it uses less digits than its factorization.

21423032144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1338939517 (or 1338939511 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21423032144 its reverse (44123032412), we get a palindrome (65546064556).

The spelling of 21423032144 in words is "twenty-one billion, four hundred twenty-three million, thirty-two thousand, one hundred forty-four".