10505215521 has 6 divisors (see below), whose sum is σ = 15174200210. Its totient is φ = 7003477008.

The previous prime is 10505215459. The next prime is 10505215531. The reversal of 10505215521 is 12551250501.

10505215521 is a `hidden beast` number, since 1 + 0 + 505 + 2 + 155 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9343155600 + 1162059921 = 96660^2 + 34089^2 .

It is not a de Polignac number, because 10505215521 - 2⁷ = 10505215393 is a prime.

It is a super-2 number, since 2×10505215521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10505215531) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583623076 + ... + 583623093.

Almost surely, 2^10505215521 is an apocalyptic number.

It is an amenable number.

10505215521 is a deficient number, since it is larger than the sum of its proper divisors (4668984689).

10505215521 is a wasteful number, since it uses less digits than its factorization.

10505215521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167246175 (or 1167246172 counting only the distinct ones).

The product of its (nonzero) digits is 2500, while the sum is 27.

The spelling of 10505215521 in words is "ten billion, five hundred five million, two hundred fifteen thousand, five hundred twenty-one".