217420137 has 24 divisors (see below), whose sum is σ = 343643040. Its totient is φ = 131369280.

The previous prime is 217420117. The next prime is 217420153. The reversal of 217420137 is 731024712.

It is a happy number.

It is not a de Polignac number, because 217420137 - 2⁷ = 217420009 is a prime.

It is a super-3 number, since 3×217420137³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 217420137.

It is not an unprimeable number, because it can be changed into a prime (217420117) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31189 + ... + 37517.

It is an arithmetic number, because the mean of its divisors is an integer number (14318460).

Almost surely, 2^217420137 is an apocalyptic number.

It is an amenable number.

217420137 is a deficient number, since it is larger than the sum of its proper divisors (126222903).

217420137 is a wasteful number, since it uses less digits than its factorization.

217420137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6693 (or 6690 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 217420137 is about 14745.1733458783. The cubic root of 217420137 is about 601.3120703608.

Adding to 217420137 its reverse (731024712), we get a palindrome (948444849).

The spelling of 217420137 in words is "two hundred seventeen million, four hundred twenty thousand, one hundred thirty-seven".