209716072406929 has 9 divisors (see below), whose sum is σ = 230514535675081. Its totient is φ = 190650830099620.

The previous prime is 209716072406921. The next prime is 209716072406957. The reversal of 209716072406929 is 929604270617902.

The square root of 209716072406929 is 14481577.

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

It is not a de Polignac number, because 209716072406929 - 2³ = 209716072406921 is a prime.

It is a super-2 number, since 2×209716072406929² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209716072406921) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 158639094 + ... + 159955600.

Almost surely, 2^{209716072406929} is an apocalyptic number.

209716072406929 is the 14481577-th square number.

209716072406929 is the 7240789-th centered octagonal number.

It is an amenable number.

209716072406929 is a deficient number, since it is larger than the sum of its proper divisors (20798463268152).

209716072406929 is an frugal number, since it uses more digits than its factorization.

209716072406929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2633036 (or 1316518 counting only the distinct ones).

The product of its (nonzero) digits is 41150592, while the sum is 64.

The spelling of 209716072406929 in words is "two hundred nine trillion, seven hundred sixteen billion, seventy-two million, four hundred six thousand, nine hundred twenty-nine".