106661571521 has 2 divisors, whose sum is σ = 106661571522. Its totient is φ = 106661571520.

The previous prime is 106661571517. The next prime is 106661571539. The reversal of 106661571521 is 125175166601.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99168937921 + 7492633600 = 314911^2 + 86560^2 .

It is a cyclic number.

It is not a de Polignac number, because 106661571521 - 2² = 106661571517 is a prime.

It is a super-2 number, since 2×106661571521² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (106661571551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53330785760 + 53330785761.

It is an arithmetic number, because the mean of its divisors is an integer number (53330785761).

Almost surely, 2^106661571521 is an apocalyptic number.

It is an amenable number.

106661571521 is a deficient number, since it is larger than the sum of its proper divisors (1).

106661571521 is an equidigital number, since it uses as much as digits as its factorization.

106661571521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 41.

The spelling of 106661571521 in words is "one hundred six billion, six hundred sixty-one million, five hundred seventy-one thousand, five hundred twenty-one".