21026123544 has 64 divisors (see below), whose sum is σ = 53097026400. Its totient is φ = 6937933824.

The previous prime is 21026123543. The next prime is 21026123551. The reversal of 21026123544 is 44532162012.

It is a super-2 number, since 2×21026123544² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21026123543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3389854 + ... + 3396050.

Almost surely, 2^21026123544 is an apocalyptic number.

21026123544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21026123544 is an abundant number, since it is smaller than the sum of its proper divisors (32070902856).

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

21026123544 is a wasteful number, since it uses less digits than its factorization.

21026123544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7612 (or 7608 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

Adding to 21026123544 its reverse (44532162012), we get a palindrome (65558285556).

The spelling of 21026123544 in words is "twenty-one billion, twenty-six million, one hundred twenty-three thousand, five hundred forty-four".