209064997 has 4 divisors (see below), whose sum is σ = 221362956. Its totient is φ = 196767040.

The previous prime is 209064979. The next prime is 209065001. The reversal of 209064997 is 799460902.

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

It can be written as a sum of positive squares in 2 ways, for example, as 85544001 + 123520996 = 9249^2 + 11114^2 .

It is a cyclic number.

It is not a de Polignac number, because 209064997 - 2¹¹ = 209062949 is a prime.

It is a super-2 number, since 2×209064997² = 87416345941220018, 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 (209064697) 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, 6148954 + ... + 6148987.

It is an arithmetic number, because the mean of its divisors is an integer number (55340739).

Almost surely, 2^209064997 is an apocalyptic number.

It is an amenable number.

209064997 is a deficient number, since it is larger than the sum of its proper divisors (12297959).

209064997 is a wasteful number, since it uses less digits than its factorization.

209064997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12297958.

The product of its (nonzero) digits is 244944, while the sum is 46.

The square root of 209064997 is about 14459.0800883044. The cubic root of 209064997 is about 593.5087264654.

The spelling of 209064997 in words is "two hundred nine million, sixty-four thousand, nine hundred ninety-seven".