2105491521 has 16 divisors (see below), whose sum is σ = 3210015744. Its totient is φ = 1202520144.

The previous prime is 2105491513. The next prime is 2105491543. The reversal of 2105491521 is 1251945012.

It is not a de Polignac number, because 2105491521 - 2³ = 2105491513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2105491501) 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, 17836 + ... + 67298.

It is an arithmetic number, because the mean of its divisors is an integer number (200625984).

Almost surely, 2^2105491521 is an apocalyptic number.

2105491521 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2105491521 is a deficient number, since it is larger than the sum of its proper divisors (1104524223).

2105491521 is a wasteful number, since it uses less digits than its factorization.

2105491521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51500.

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 2105491521 is about 45885.6352358775. The cubic root of 2105491521 is about 1281.6944358443.

It can be divided in two parts, 2105491 and 521, that added together give a palindrome (2106012).

The spelling of 2105491521 in words is "two billion, one hundred five million, four hundred ninety-one thousand, five hundred twenty-one".