1219877820 has 240 divisors, whose sum is σ = 4422559680. Its totient is φ = 275705856.

The previous prime is 1219877803. The next prime is 1219877849. The reversal of 1219877820 is 287789121.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1099426 + ... + 1100534.

It is an arithmetic number, because the mean of its divisors is an integer number (18427332).

Almost surely, 2^1219877820 is an apocalyptic number.

1219877820 is a gapful number since it is divisible by the number (10) 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 1219877820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2211279840).

1219877820 is an abundant number, since it is smaller than the sum of its proper divisors (3202681860).

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

1219877820 is a wasteful number, since it uses less digits than its factorization.

1219877820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1234 (or 1223 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 1219877820 is about 34926.7493477421. The cubic root of 1219877820 is about 1068.4940587497.

The spelling of 1219877820 in words is "one billion, two hundred nineteen million, eight hundred seventy-seven thousand, eight hundred twenty".