21544515152 has 10 divisors (see below), whose sum is σ = 41742498138. Its totient is φ = 10772257568.

The previous prime is 21544515149. The next prime is 21544515197. The reversal of 21544515152 is 25151544512.

It can be written as a sum of positive squares in only one way, i.e., 14298419776 + 7246095376 = 119576^2 + 85124^2 .

It is a super-2 number, since 2×21544515152² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 673266083 + ... + 673266114.

Almost surely, 2^21544515152 is an apocalyptic number.

It is an amenable number.

21544515152 is a deficient number, since it is larger than the sum of its proper divisors (20197982986).

21544515152 is a wasteful number, since it uses less digits than its factorization.

21544515152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1346532205 (or 1346532199 counting only the distinct ones).

The product of its digits is 40000, while the sum is 35.

The spelling of 21544515152 in words is "twenty-one billion, five hundred forty-four million, five hundred fifteen thousand, one hundred fifty-two".