217881053 has 6 divisors (see below), whose sum is σ = 235930554. Its totient is φ = 201120816.

The previous prime is 217881023. The next prime is 217881067. The reversal of 217881053 is 350188712.

It can be written as a sum of positive squares in 3 ways, for example, as 407044 + 217474009 = 638^2 + 14747^2 .

It is not a de Polignac number, because 217881053 - 2¹⁰ = 217880029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217881023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 644450 + ... + 644787.

It is an arithmetic number, because the mean of its divisors is an integer number (39321759).

Almost surely, 2^217881053 is an apocalyptic number.

It is an amenable number.

217881053 is a deficient number, since it is larger than the sum of its proper divisors (18049501).

217881053 is a wasteful number, since it uses less digits than its factorization.

217881053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289263 (or 1289250 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 217881053 is about 14760.7944569390. The cubic root of 217881053 is about 601.7366841046.

The spelling of 217881053 in words is "two hundred seventeen million, eight hundred eighty-one thousand, fifty-three".