21505010045 has 8 divisors (see below), whose sum is σ = 25806871296. Its totient is φ = 17203435216.

The previous prime is 21505010041. The next prime is 21505010053. The reversal of 21505010045 is 54001050512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21505010045 - 2² = 21505010041 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21505010045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21505010041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164144 + ... + 264486.

It is an arithmetic number, because the mean of its divisors is an integer number (3225858912).

Almost surely, 2^21505010045 is an apocalyptic number.

It is an amenable number.

21505010045 is a deficient number, since it is larger than the sum of its proper divisors (4301861251).

21505010045 is a wasteful number, since it uses less digits than its factorization.

21505010045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143211.

The product of its (nonzero) digits is 1000, while the sum is 23.

Adding to 21505010045 its reverse (54001050512), we get a palindrome (75506060557).

The spelling of 21505010045 in words is "twenty-one billion, five hundred five million, ten thousand, forty-five".