2131778 has 24 divisors (see below), whose sum is σ = 3677184. Its totient is φ = 924440.

The previous prime is 2131771. The next prime is 2131793. The reversal of 2131778 is 8771312.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2131778.

It is not an unprimeable number, because it can be changed into a prime (2131771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5375 + ... + 5757.

It is an arithmetic number, because the mean of its divisors is an integer number (153216).

2^2131778 is an apocalyptic number.

2131778 is a deficient number, since it is larger than the sum of its proper divisors (1545406).

2131778 is a wasteful number, since it uses less digits than its factorization.

2131778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 419 counting only the distinct ones).

The product of its digits is 2352, while the sum is 29.

The square root of 2131778 is about 1460.0609576316. The cubic root of 2131778 is about 128.7006258036.

It can be divided in two parts, 213 and 1778, that added together give a palindrome (1991).

The spelling of 2131778 in words is "two million, one hundred thirty-one thousand, seven hundred seventy-eight".