2108921929 has 9 divisors (see below), whose sum is σ = 2226680967. Its totient is φ = 1997099424.

The previous prime is 2108921923. The next prime is 2108921939. The reversal of 2108921929 is 9291298012.

The square root of 2108921929 is 45923.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 2053449225 + 55472704 = 45315^2 + 7448^2 .

It is not a de Polignac number, because 2108921929 - 2³ = 2108921921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2108921921) 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 8 ways as a sum of consecutive naturals, for example, 871329 + ... + 873745.

Almost surely, 2^2108921929 is an apocalyptic number.

2108921929 is the 45923-rd square number.

2108921929 is the 22962-nd centered octagonal number.

It is an amenable number.

2108921929 is a deficient number, since it is larger than the sum of its proper divisors (117759038).

2108921929 is an frugal number, since it uses more digits than its factorization.

2108921929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4872 (or 2436 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 43.

The cubic root of 2108921929 is about 1282.3901323349.

Multiplying 2108921929 by its product of nonzero digits (46656), we get a square (98393861519424 = 9919368²).

The spelling of 2108921929 in words is "two billion, one hundred eight million, nine hundred twenty-one thousand, nine hundred twenty-nine".