999999888887772 has 72 divisors (see below), whose sum is σ = 2557080691583600. Its totient is φ = 329490082706688.

The previous prime is 999999888887759. The next prime is 999999888887809. The reversal of 999999888887772 is 277788888999999.

It is a super-2 number, since 2×999999888887772² (a number of 31 digits) contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

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, 435186193 + ... + 437478024.

Almost surely, 2^{999999888887772} is an apocalyptic number.

It is an amenable number.

999999888887772 is an abundant number, since it is smaller than the sum of its proper divisors (1557080802695828).

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

999999888887772 is a wasteful number, since it uses less digits than its factorization.

999999888887772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872664595 (or 872664590 counting only the distinct ones).

The product of its digits is 11946181459968, while the sum is 117.

The spelling of 999999888887772 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, eight hundred eighty-eight million, eight hundred eighty-seven thousand, seven hundred seventy-two".