209609276961 has 16 divisors (see below), whose sum is σ = 319427225600. Its totient is φ = 119768249808.

The previous prime is 209609276953. The next prime is 209609276969. The reversal of 209609276961 is 169672906902.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (209609276953) and next prime (209609276969).

It is not a de Polignac number, because 209609276961 - 2³ = 209609276953 is a prime.

It is a super-2 number, since 2×209609276961² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (209609276969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43321 + ... + 648918.

It is an arithmetic number, because the mean of its divisors is an integer number (19964201600).

Almost surely, 2^209609276961 is an apocalyptic number.

209609276961 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

209609276961 is a deficient number, since it is larger than the sum of its proper divisors (109817948639).

209609276961 is a wasteful number, since it uses less digits than its factorization.

209609276961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706668.

The product of its (nonzero) digits is 4408992, while the sum is 57.

The spelling of 209609276961 in words is "two hundred nine billion, six hundred nine million, two hundred seventy-six thousand, nine hundred sixty-one".