660521131 has 2 divisors, whose sum is σ = 660521132. Its totient is φ = 660521130.

The previous prime is 660521117. The next prime is 660521159. The reversal of 660521131 is 131125066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660521131 - 2²¹ = 658423979 is a prime.

It is a super-2 number, since 2×660521131² = 872576328995038322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 660521096 and 660521105.

It is not a weakly prime, because it can be changed into another prime (660521101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330260565 + 330260566.

It is an arithmetic number, because the mean of its divisors is an integer number (330260566).

Almost surely, 2^660521131 is an apocalyptic number.

660521131 is a deficient number, since it is larger than the sum of its proper divisors (1).

660521131 is an equidigital number, since it uses as much as digits as its factorization.

660521131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 660521131 is about 25700.6056543421. The cubic root of 660521131 is about 870.8878640201.

Adding to 660521131 its reverse (131125066), we get a palindrome (791646197).

The spelling of 660521131 in words is "six hundred sixty million, five hundred twenty-one thousand, one hundred thirty-one".