1780168138 has 12 divisors (see below), whose sum is σ = 3106211922. Its totient is φ = 762929160.

The previous prime is 1780168129. The next prime is 1780168157. The reversal of 1780168138 is 8318610871.

It can be written as a sum of positive squares in only one way, i.e., 1712056129 + 68112009 = 41377^2 + 8253^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1780168094 and 1780168103.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9082393 + ... + 9082588.

Almost surely, 2^1780168138 is an apocalyptic number.

1780168138 is a deficient number, since it is larger than the sum of its proper divisors (1326043784).

1780168138 is a wasteful number, since it uses less digits than its factorization.

1780168138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18164997 (or 18164990 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 1780168138 is about 42192.0387988066. The cubic root of 1780168138 is about 1211.9564319898.

The spelling of 1780168138 in words is "one billion, seven hundred eighty million, one hundred sixty-eight thousand, one hundred thirty-eight".