218038985521 has 16 divisors (see below), whose sum is σ = 252801176320. Its totient is φ = 184196229120.

The previous prime is 218038985513. The next prime is 218038985551. The reversal of 218038985521 is 125589830812.

It is a cyclic number.

It is not a de Polignac number, because 218038985521 - 2³ = 218038985513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (218038985551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 502581 + ... + 829858.

It is an arithmetic number, because the mean of its divisors is an integer number (15800073520).

Almost surely, 2^218038985521 is an apocalyptic number.

It is an amenable number.

218038985521 is a deficient number, since it is larger than the sum of its proper divisors (34762190799).

218038985521 is a wasteful number, since it uses less digits than its factorization.

218038985521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332784.

The product of its (nonzero) digits is 1382400, while the sum is 52.

The spelling of 218038985521 in words is "two hundred eighteen billion, thirty-eight million, nine hundred eighty-five thousand, five hundred twenty-one".