2780561238 has 128 divisors (see below), whose sum is σ = 7188894720. Its totient is φ = 697213440.

The previous prime is 2780561237. The next prime is 2780561243. The reversal of 2780561238 is 8321650872.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 2780561238.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2780561237) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1059568 + ... + 1062188.

It is an arithmetic number, because the mean of its divisors is an integer number (56163240).

Almost surely, 2^2780561238 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2780561238, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3594447360).

2780561238 is an abundant number, since it is smaller than the sum of its proper divisors (4408333482).

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

2780561238 is a wasteful number, since it uses less digits than its factorization.

2780561238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742.

The product of its (nonzero) digits is 161280, while the sum is 42.

The square root of 2780561238 is about 52731.0272799611. The cubic root of 2780561238 is about 1406.1904843474.

The spelling of 2780561238 in words is "two billion, seven hundred eighty million, five hundred sixty-one thousand, two hundred thirty-eight".