217779977712 has 160 divisors (see below), whose sum is σ = 619596843264. Its totient is φ = 65367244800.

The previous prime is 217779977711. The next prime is 217779977713.

217779977712 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (217779977711) and next prime (217779977713).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217779977711) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27434608 + ... + 27442544.

Almost surely, 2^217779977712 is an apocalyptic number.

217779977712 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217779977712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309798421632).

217779977712 is an abundant number, since it is smaller than the sum of its proper divisors (401816865552).

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

217779977712 is a wasteful number, since it uses less digits than its factorization.

217779977712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8447 (or 8441 counting only the distinct ones).

The product of its digits is 38118276, while the sum is 66.

The spelling of 217779977712 in words is "two hundred seventeen billion, seven hundred seventy-nine million, nine hundred seventy-seven thousand, seven hundred twelve".