106805429721 has 27 divisors (see below), whose sum is σ = 158188614493. Its totient is φ = 69440801280.

The previous prime is 106805429719. The next prime is 106805429741. The reversal of 106805429721 is 127924508601.

The square root of 106805429721 is 326811.

It is a perfect power (a square), and thus also a powerful number.

106805429721 is a `hidden beast` number, since 1 + 0 + 6 + 80 + 542 + 9 + 7 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 16963760025 + 89841669696 = 130245^2 + 299736^2 .

It is not a de Polignac number, because 106805429721 - 2¹ = 106805429719 is a prime.

It is a super-2 number, since 2×106805429721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (106805429741) 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 26 ways as a sum of consecutive naturals, for example, 40196425 + ... + 40199081.

Almost surely, 2^106805429721 is an apocalyptic number.

106805429721 is the 326811-st square number.

106805429721 is the 163406-th centered octagonal number.

It is an amenable number.

106805429721 is a deficient number, since it is larger than the sum of its proper divisors (51383184772).

106805429721 is an frugal number, since it uses more digits than its factorization.

106805429721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5402 (or 2701 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 106805429721 in words is "one hundred six billion, eight hundred five million, four hundred twenty-nine thousand, seven hundred twenty-one".