21544123513 has 8 divisors (see below), whose sum is σ = 23543419680. Its totient is φ = 19551617280.

The previous prime is 21544123429. The next prime is 21544123553. The reversal of 21544123513 is 31532144512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21544123513 is a prime.

It is a super-2 number, since 2×21544123513² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21544123553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1690843 + ... + 1703536.

It is an arithmetic number, because the mean of its divisors is an integer number (2942927460).

Almost surely, 2^21544123513 is an apocalyptic number.

It is an amenable number.

21544123513 is a deficient number, since it is larger than the sum of its proper divisors (1999296167).

21544123513 is a wasteful number, since it uses less digits than its factorization.

21544123513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3394967.

The product of its digits is 14400, while the sum is 31.

The spelling of 21544123513 in words is "twenty-one billion, five hundred forty-four million, one hundred twenty-three thousand, five hundred thirteen".