105021521 has 16 divisors (see below), whose sum is σ = 119218176. Its totient is φ = 91650000.

The previous prime is 105021509. The next prime is 105021571. The reversal of 105021521 is 125120501.

It is a cyclic number.

It is not a de Polignac number, because 105021521 - 2¹⁸ = 104759377 is a prime.

It is a super-2 number, since 2×105021521² = 22059039746306882, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 105021521.

It is not an unprimeable number, because it can be changed into a prime (105021571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43496 + ... + 45846.

It is an arithmetic number, because the mean of its divisors is an integer number (7451136).

Almost surely, 2^105021521 is an apocalyptic number.

105021521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

105021521 is a deficient number, since it is larger than the sum of its proper divisors (14196655).

105021521 is a wasteful number, since it uses less digits than its factorization.

105021521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2524.

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 105021521 is about 10248.0008294301. Note that the first 3 decimals coincide. The cubic root of 105021521 is about 471.8016274146.

Subtracting from 105021521 its sum of digits (17), we obtain a square (105021504 = 10248²).

The spelling of 105021521 in words is "one hundred five million, twenty-one thousand, five hundred twenty-one".