65940209 has 4 divisors (see below), whose sum is σ = 66032640. Its totient is φ = 65847780.

The previous prime is 65940197. The next prime is 65940221. The reversal of 65940209 is 90204956.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (65940197) and next prime (65940221).

It is a cyclic number.

It is not a de Polignac number, because 65940209 - 2⁸ = 65939953 is a prime.

It is a super-2 number, since 2×65940209² = 8696222325927362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65940269) 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, 45137 + ... + 46574.

It is an arithmetic number, because the mean of its divisors is an integer number (16508160).

Almost surely, 2^65940209 is an apocalyptic number.

It is an amenable number.

65940209 is a deficient number, since it is larger than the sum of its proper divisors (92431).

65940209 is an equidigital number, since it uses as much as digits as its factorization.

65940209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92430.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 65940209 is about 8120.3576891662. The cubic root of 65940209 is about 404.0019299486.

The spelling of 65940209 in words is "sixty-five million, nine hundred forty thousand, two hundred nine".