106405666521 has 64 divisors (see below), whose sum is σ = 185530798080. Its totient is φ = 52597923840.

The previous prime is 106405666487. The next prime is 106405666537. The reversal of 106405666521 is 125666504601.

It is not a de Polignac number, because 106405666521 - 2¹⁵ = 106405633753 is a prime.

It is a super-2 number, since 2×106405666521² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (106405666021) 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 63 ways as a sum of consecutive naturals, for example, 973525 + ... + 1077293.

It is an arithmetic number, because the mean of its divisors is an integer number (2898918720).

Almost surely, 2^106405666521 is an apocalyptic number.

106405666521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

106405666521 is a deficient number, since it is larger than the sum of its proper divisors (79125131559).

106405666521 is a wasteful number, since it uses less digits than its factorization.

106405666521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104006.

The product of its (nonzero) digits is 259200, while the sum is 42.

The spelling of 106405666521 in words is "one hundred six billion, four hundred five million, six hundred sixty-six thousand, five hundred twenty-one".