217881040640 has 36 divisors (see below), whose sum is σ = 521893183224. Its totient is φ = 87152415744.

The previous prime is 217881040631. The next prime is 217881040661. The reversal of 217881040640 is 46040188712.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85108502 + ... + 85111061.

Almost surely, 2^217881040640 is an apocalyptic number.

217881040640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217881040640 is an abundant number, since it is smaller than the sum of its proper divisors (304012142584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217881040640 is an equidigital number, since it uses as much as digits as its factorization.

217881040640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170219584 (or 170219570 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 41.

The spelling of 217881040640 in words is "two hundred seventeen billion, eight hundred eighty-one million, forty thousand, six hundred forty".