21516530044 has 6 divisors (see below), whose sum is σ = 37653927584. Its totient is φ = 10758265020.

The previous prime is 21516530023. The next prime is 21516530053. The reversal of 21516530044 is 44003561512.

It is a happy number.

It is a super-2 number, since 2×21516530044² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21516529988 and 21516530015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2689566252 + ... + 2689566259.

Almost surely, 2^21516530044 is an apocalyptic number.

It is an amenable number.

21516530044 is a deficient number, since it is larger than the sum of its proper divisors (16137397540).

21516530044 is a wasteful number, since it uses less digits than its factorization.

21516530044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5379132515 (or 5379132513 counting only the distinct ones).

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

The spelling of 21516530044 in words is "twenty-one billion, five hundred sixteen million, five hundred thirty thousand, forty-four".