309640238 has 8 divisors (see below), whose sum is σ = 468801432. Its totient is φ = 153373096.

The previous prime is 309640229. The next prime is 309640259. The reversal of 309640238 is 832046903.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 309640198 and 309640207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 723245 + ... + 723672.

It is an arithmetic number, because the mean of its divisors is an integer number (58600179).

Almost surely, 2^309640238 is an apocalyptic number.

309640238 is a deficient number, since it is larger than the sum of its proper divisors (159161194).

309640238 is a wasteful number, since it uses less digits than its factorization.

309640238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1447026.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 309640238 is about 17596.5973415317. The cubic root of 309640238 is about 676.5280338620.

It can be divided in two parts, 3096 and 40238, that added together give a palindrome (43334).

The spelling of 309640238 in words is "three hundred nine million, six hundred forty thousand, two hundred thirty-eight".