217812953 has 4 divisors (see below), whose sum is σ = 217924560. Its totient is φ = 217701348.

The previous prime is 217812949. The next prime is 217812961. The reversal of 217812953 is 359218712.

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 a cyclic number.

It is not a de Polignac number, because 217812953 - 2² = 217812949 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217812943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52823 + ... + 56796.

It is an arithmetic number, because the mean of its divisors is an integer number (54481140).

Almost surely, 2^217812953 is an apocalyptic number.

It is an amenable number.

217812953 is a deficient number, since it is larger than the sum of its proper divisors (111607).

217812953 is a wasteful number, since it uses less digits than its factorization.

217812953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111606.

The product of its digits is 30240, while the sum is 38.

The square root of 217812953 is about 14758.4874902545. The cubic root of 217812953 is about 601.6739854629.

The spelling of 217812953 in words is "two hundred seventeen million, eight hundred twelve thousand, nine hundred fifty-three".