1780220988 has 108 divisors (see below), whose sum is σ = 5569029648. Its totient is φ = 469497600.

The previous prime is 1780220971. The next prime is 1780220989. The reversal of 1780220988 is 8890220871.

It is a happy number.

It is a super-2 number, since 2×1780220988² = 6338373532231392288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1780220989) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 21688 + ... + 63488.

Almost surely, 2^1780220988 is an apocalyptic number.

1780220988 is a gapful number since it is divisible by the number (18) 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 1780220988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2784514824).

1780220988 is an abundant number, since it is smaller than the sum of its proper divisors (3788808660).

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

1780220988 is a wasteful number, since it uses less digits than its factorization.

1780220988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41844 (or 41826 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 1780220988 is about 42192.6650971469. The cubic root of 1780220988 is about 1211.9684254755.

The spelling of 1780220988 in words is "one billion, seven hundred eighty million, two hundred twenty thousand, nine hundred eighty-eight".