209764423 has 4 divisors (see below), whose sum is σ = 228833928. Its totient is φ = 190694920.

The previous prime is 209764417. The next prime is 209764447. The reversal of 209764423 is 324467902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 209764423 - 2⁵ = 209764391 is a prime.

It is a super-2 number, since 2×209764423² = 88002226313045858, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209764463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9534736 + ... + 9534757.

It is an arithmetic number, because the mean of its divisors is an integer number (57208482).

Almost surely, 2^209764423 is an apocalyptic number.

209764423 is a deficient number, since it is larger than the sum of its proper divisors (19069505).

209764423 is a wasteful number, since it uses less digits than its factorization.

209764423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19069504.

The product of its (nonzero) digits is 72576, while the sum is 37.

The square root of 209764423 is about 14483.2462866583. The cubic root of 209764423 is about 594.1698500022.

The spelling of 209764423 in words is "two hundred nine million, seven hundred sixty-four thousand, four hundred twenty-three".