21042040144 has 10 divisors (see below), whose sum is σ = 40768952810. Its totient is φ = 10521020064.

The previous prime is 21042040133. The next prime is 21042040157. The reversal of 21042040144 is 44104024012.

It can be written as a sum of positive squares in only one way, i.e., 13101091600 + 7940948544 = 114460^2 + 89112^2 .

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, 657563739 + ... + 657563770.

It is an arithmetic number, because the mean of its divisors is an integer number (4076895281).

Almost surely, 2^21042040144 is an apocalyptic number.

It is an amenable number.

21042040144 is a deficient number, since it is larger than the sum of its proper divisors (19726912666).

21042040144 is a wasteful number, since it uses less digits than its factorization.

21042040144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315127517 (or 1315127511 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 22.

Adding to 21042040144 its reverse (44104024012), we get a palindrome (65146064156).

The spelling of 21042040144 in words is "twenty-one billion, forty-two million, forty thousand, one hundred forty-four".