21530105552 has 10 divisors (see below), whose sum is σ = 41714579538. Its totient is φ = 10765052768.

The previous prime is 21530105483. The next prime is 21530105561. The reversal of 21530105552 is 25550103512.

It can be written as a sum of positive squares in only one way, i.e., 16038702736 + 5491402816 = 126644^2 + 74104^2 .

It is a super-2 number, since 2×21530105552² (a number of 21 digits) contains 22 as substring.

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, 672815783 + ... + 672815814.

Almost surely, 2^21530105552 is an apocalyptic number.

It is an amenable number.

21530105552 is a deficient number, since it is larger than the sum of its proper divisors (20184473986).

21530105552 is a wasteful number, since it uses less digits than its factorization.

21530105552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1345631605 (or 1345631599 counting only the distinct ones).

The product of its (nonzero) digits is 7500, while the sum is 29.

The spelling of 21530105552 in words is "twenty-one billion, five hundred thirty million, one hundred five thousand, five hundred fifty-two".