1778720916 has 192 divisors, whose sum is σ = 5225472000. Its totient is φ = 459723264.

The previous prime is 1778720903. The next prime is 1778720941. The reversal of 1778720916 is 6190278771.

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, 2969185 + ... + 2969783.

It is an arithmetic number, because the mean of its divisors is an integer number (27216000).

Almost surely, 2^1778720916 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 1778720916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2612736000).

1778720916 is an abundant number, since it is smaller than the sum of its proper divisors (3446751084).

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

1778720916 is a wasteful number, since it uses less digits than its factorization.

1778720916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718 (or 716 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 48.

The square root of 1778720916 is about 42174.8848961085. The cubic root of 1778720916 is about 1211.6279151685.

The spelling of 1778720916 in words is "one billion, seven hundred seventy-eight million, seven hundred twenty thousand, nine hundred sixteen".