21060183781 has 12 divisors (see below), whose sum is σ = 26383088172. Its totient is φ = 16663002048.

The previous prime is 21060183769. The next prime is 21060183803. The reversal of 21060183781 is 18738106012.

It can be written as a sum of positive squares in 2 ways, for example, as 12136547556 + 8923636225 = 110166^2 + 94465^2 .

It is not a de Polignac number, because 21060183781 - 2¹¹ = 21060181733 is a prime.

It is a super-2 number, since 2×21060183781² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21060183781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060183701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16530120 + ... + 16531393.

It is an arithmetic number, because the mean of its divisors is an integer number (2198590681).

Almost surely, 2^21060183781 is an apocalyptic number.

It is an amenable number.

21060183781 is a deficient number, since it is larger than the sum of its proper divisors (5322904391).

21060183781 is a wasteful number, since it uses less digits than its factorization.

21060183781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33061540 (or 33061533 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 37.

Adding to 21060183781 its reverse (18738106012), we get a palindrome (39798289793).

The spelling of 21060183781 in words is "twenty-one billion, sixty million, one hundred eighty-three thousand, seven hundred eighty-one".