1838778381 has 32 divisors (see below), whose sum is σ = 3052099200. Its totient is φ = 1084285440.

The previous prime is 1838778349. The next prime is 1838778413.

1838778381 is a `hidden beast` number, since 183 + 87 + 7 + 8 + 381 = 666.

1838778381 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (1838778349) and next prime (1838778413).

It is not a de Polignac number, because 1838778381 - 2⁵ = 1838778349 is a prime.

It is a super-2 number, since 2×1838778381² = 6762211868865962322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1838778881) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72676 + ... + 94653.

It is an arithmetic number, because the mean of its divisors is an integer number (95378100).

Almost surely, 2^1838778381 is an apocalyptic number.

1838778381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1838778381 is a deficient number, since it is larger than the sum of its proper divisors (1213320819).

1838778381 is a wasteful number, since it uses less digits than its factorization.

1838778381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167386 (or 167380 counting only the distinct ones).

The product of its digits is 1806336, while the sum is 54.

The square root of 1838778381 is about 42880.9792448820. The cubic root of 1838778381 is about 1225.1138877317.

The spelling of 1838778381 in words is "one billion, eight hundred thirty-eight million, seven hundred seventy-eight thousand, three hundred eighty-one".