1878781 has 2 divisors, whose sum is σ = 1878782. Its totient is φ = 1878780.

The previous prime is 1878769. The next prime is 1878791.

1878781 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1779556 + 99225 = 1334^2 + 315^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 1878781 - 2¹¹ = 1876733 is a prime.

It is a super-2 number, since 2×1878781² = 7059636091922, which contains 22 as substring.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1878791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 939390 + 939391.

It is an arithmetic number, because the mean of its divisors is an integer number (939391).

2^1878781 is an apocalyptic number.

It is an amenable number.

1878781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1878781 is an equidigital number, since it uses as much as digits as its factorization.

1878781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25088, while the sum is 40.

The square root of 1878781 is about 1370.6863244375. The cubic root of 1878781 is about 123.3934347119.

The spelling of 1878781 in words is "one million, eight hundred seventy-eight thousand, seven hundred eighty-one".