217874055631 has 2 divisors, whose sum is σ = 217874055632. Its totient is φ = 217874055630.

The previous prime is 217874055559. The next prime is 217874055643. The reversal of 217874055631 is 136550478712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217874055631 is a prime.

It is a super-2 number, since 2×217874055631² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217874055661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108937027815 + 108937027816.

It is an arithmetic number, because the mean of its divisors is an integer number (108937027816).

Almost surely, 2^217874055631 is an apocalyptic number.

217874055631 is a deficient number, since it is larger than the sum of its proper divisors (1).

217874055631 is an equidigital number, since it uses as much as digits as its factorization.

217874055631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1411200, while the sum is 49.

The spelling of 217874055631 in words is "two hundred seventeen billion, eight hundred seventy-four million, fifty-five thousand, six hundred thirty-one".