999764220 has 192 divisors, whose sum is σ = 3648347136. Its totient is φ = 198512640.

The previous prime is 999764219. The next prime is 999764231. The reversal of 999764220 is 22467999.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 999764220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 87435 + ... + 98205.

It is an arithmetic number, because the mean of its divisors is an integer number (19001808).

Almost surely, 2^999764220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999764220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1824173568).

999764220 is an abundant number, since it is smaller than the sum of its proper divisors (2648582916).

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

999764220 is a wasteful number, since it uses less digits than its factorization.

999764220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10820 (or 10818 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 48.

The square root of 999764220 is about 31619.0483727768. The cubic root of 999764220 is about 999.9214004889.

It can be divided in two parts, 99976 and 4220, that added together give a triangular number (104196 = T₄₅₆).

The spelling of 999764220 in words is "nine hundred ninety-nine million, seven hundred sixty-four thousand, two hundred twenty".