217283331780 has 72 divisors (see below), whose sum is σ = 659167891200. Its totient is φ = 57935618112.

The previous prime is 217283331773. The next prime is 217283331851. The reversal of 217283331780 is 87133382712.

It is a happy number.

217283331780 is a `hidden beast` number, since 2 + 172 + 83 + 331 + 78 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1631341 + ... + 1759499.

It is an arithmetic number, because the mean of its divisors is an integer number (9155109600).

Almost surely, 2^217283331780 is an apocalyptic number.

217283331780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217283331780 is an abundant number, since it is smaller than the sum of its proper divisors (441884559420).

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

217283331780 is a wasteful number, since it uses less digits than its factorization.

217283331780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137593 (or 137588 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 217283331780 in words is "two hundred seventeen billion, two hundred eighty-three million, three hundred thirty-one thousand, seven hundred eighty".