21123543044 has 12 divisors (see below), whose sum is σ = 38240897100. Its totient is φ = 10197572448.

The previous prime is 21123543043. The next prime is 21123543071. The reversal of 21123543044 is 44034532112.

It can be written as a sum of positive squares in 2 ways, for example, as 9117958144 + 12005584900 = 95488^2 + 109570^2 .

It is a super-4 number, since 4×21123543044⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a junction number, because it is equal to n+sod(n) for n = 21123542998 and 21123543016.

It is not an unprimeable number, because it can be changed into a prime (21123543043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91049639 + ... + 91049870.

It is an arithmetic number, because the mean of its divisors is an integer number (3186741425).

Almost surely, 2^21123543044 is an apocalyptic number.

It is an amenable number.

21123543044 is a deficient number, since it is larger than the sum of its proper divisors (17117354056).

21123543044 is a wasteful number, since it uses less digits than its factorization.

21123543044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182099542 (or 182099540 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The spelling of 21123543044 in words is "twenty-one billion, one hundred twenty-three million, five hundred forty-three thousand, forty-four".