21040123044 has 24 divisors (see below), whose sum is σ = 49232705760. Its totient is φ = 6993505024.

The previous prime is 21040123037. The next prime is 21040123051. The reversal of 21040123044 is 44032104012.

It is an interprime number because it is at equal distance from previous prime (21040123037) and next prime (21040123051).

It is a self number, because there is not a number n which added to its sum of digits gives 21040123044.

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, 2479254 + ... + 2487725.

It is an arithmetic number, because the mean of its divisors is an integer number (2051362740).

Almost surely, 2^21040123044 is an apocalyptic number.

It is an amenable number.

21040123044 is an abundant number, since it is smaller than the sum of its proper divisors (28192582716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21040123044 is a wasteful number, since it uses less digits than its factorization.

21040123044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4967339 (or 4967337 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21040123044 its reverse (44032104012), we get a palindrome (65072227056).

The spelling of 21040123044 in words is "twenty-one billion, forty million, one hundred twenty-three thousand, forty-four".