7521638660 has 24 divisors (see below), whose sum is σ = 15802309656. Its totient is φ = 3007347200.

The previous prime is 7521638651. The next prime is 7521638669. The reversal of 7521638660 is 668361257.

It is an interprime number because it is at equal distance from previous prime (7521638651) and next prime (7521638669).

It can be written as a sum of positive squares in 4 ways, for example, as 2289431104 + 5232207556 = 47848^2 + 72334^2 .

It is not an unprimeable number, because it can be changed into a prime (7521638669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33941 + ... + 127260.

It is an arithmetic number, because the mean of its divisors is an integer number (658429569).

Almost surely, 2^7521638660 is an apocalyptic number.

It is an amenable number.

7521638660 is an abundant number, since it is smaller than the sum of its proper divisors (8280670996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7521638660 is a wasteful number, since it uses less digits than its factorization.

7521638660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163543 (or 163541 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 44.

The square root of 7521638660 is about 86727.3812587467. The cubic root of 7521638660 is about 1959.3145128205.

The spelling of 7521638660 in words is "seven billion, five hundred twenty-one million, six hundred thirty-eight thousand, six hundred sixty".