2156787 has 10 divisors (see below), whose sum is σ = 3221988. Its totient is φ = 1437804.

The previous prime is 2156761. The next prime is 2156789. The reversal of 2156787 is 7876512.

2156787 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2156787 - 2⁷ = 2156659 is a prime.

It is an Ulam number.

2156787 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2156789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 13233 + ... + 13394.

2^2156787 is an apocalyptic number.

2156787 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

2156787 is a deficient number, since it is larger than the sum of its proper divisors (1065201).

2156787 is an equidigital number, since it uses as much as digits as its factorization.

2156787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26639 (or 26630 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 2156787 is about 1468.6003540787. The cubic root of 2156787 is about 129.2019551634.

The spelling of 2156787 in words is "two million, one hundred fifty-six thousand, seven hundred eighty-seven".