2128761 has 20 divisors (see below), whose sum is σ = 3262644. Its totient is φ = 1382400.

The previous prime is 2128751. The next prime is 2128769. The reversal of 2128761 is 1678212.

It can be written as a sum of positive squares in 2 ways, for example, as 962361 + 1166400 = 981^2 + 1080^2 .

It is not a de Polignac number, because 2128761 - 2⁶ = 2128697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2128769) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3001 + ... + 3641.

2^2128761 is an apocalyptic number.

It is an amenable number.

2128761 is a deficient number, since it is larger than the sum of its proper divisors (1133883).

2128761 is an equidigital number, since it uses as much as digits as its factorization.

2128761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694 (or 685 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 2128761 is about 1459.0274157808. The cubic root of 2128761 is about 128.6398825948.

It can be divided in two parts, 21 and 28761, that added together give a palindrome (28782).

The spelling of 2128761 in words is "two million, one hundred twenty-eight thousand, seven hundred sixty-one".