7980521905 has 16 divisors (see below), whose sum is σ = 10331283024. Its totient is φ = 5895485440.

The previous prime is 7980521903. The next prime is 7980521917. The reversal of 7980521905 is 5091250897.

It can be written as a sum of positive squares in 8 ways, for example, as 161010721 + 7819511184 = 12689^2 + 88428^2 .

It is not a de Polignac number, because 7980521905 - 2¹ = 7980521903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7980521903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 881236 + ... + 890245.

It is an arithmetic number, because the mean of its divisors is an integer number (645705189).

Almost surely, 2^7980521905 is an apocalyptic number.

It is an amenable number.

7980521905 is a deficient number, since it is larger than the sum of its proper divisors (2350761119).

7980521905 is a wasteful number, since it uses less digits than its factorization.

7980521905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1771556.

The product of its (nonzero) digits is 226800, while the sum is 46.

The square root of 7980521905 is about 89333.7668801669. The cubic root of 7980521905 is about 1998.3755062840.

The spelling of 7980521905 in words is "seven billion, nine hundred eighty million, five hundred twenty-one thousand, nine hundred five".