12777861 has 16 divisors (see below), whose sum is σ = 18011840. Its totient is φ = 8035200.

The previous prime is 12777827. The next prime is 12777889. The reversal of 12777861 is 16877721.

12777861 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12777861 - 2¹⁴ = 12761477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12777161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20961 + ... + 21561.

It is an arithmetic number, because the mean of its divisors is an integer number (1125740).

Almost surely, 2^12777861 is an apocalyptic number.

It is an amenable number.

12777861 is a deficient number, since it is larger than the sum of its proper divisors (5233979).

12777861 is a wasteful number, since it uses less digits than its factorization.

12777861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 996.

The product of its digits is 32928, while the sum is 39.

The square root of 12777861 is about 3574.6134056706. The cubic root of 12777861 is about 233.7864770016.

The spelling of 12777861 in words is "twelve million, seven hundred seventy-seven thousand, eight hundred sixty-one".