2261778816 has 128 divisors (see below), whose sum is σ = 6678339840. Its totient is φ = 672389120.

The previous prime is 2261778793. The next prime is 2261778839. The reversal of 2261778816 is 6188771622.

It is an interprime number because it is at equal distance from previous prime (2261778793) and next prime (2261778839).

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-3 number, since 3×2261778816³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 218821 + ... + 228923.

It is an arithmetic number, because the mean of its divisors is an integer number (52174530).

Almost surely, 2^2261778816 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 2261778816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3339169920).

2261778816 is an abundant number, since it is smaller than the sum of its proper divisors (4416561024).

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

2261778816 is a wasteful number, since it uses less digits than its factorization.

2261778816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10184 (or 10172 counting only the distinct ones).

The product of its digits is 451584, while the sum is 48.

The square root of 2261778816 is about 47558.1624539889. The cubic root of 2261778816 is about 1312.6533281916.

The spelling of 2261778816 in words is "two billion, two hundred sixty-one million, seven hundred seventy-eight thousand, eight hundred sixteen".