2145771 has 20 divisors (see below), whose sum is σ = 3267000. Its totient is φ = 1403136.

The previous prime is 2145769. The next prime is 2145779. The reversal of 2145771 is 1775412.

It is not a de Polignac number, because 2145771 - 2¹ = 2145769 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4555 + ... + 5003.

It is an arithmetic number, because the mean of its divisors is an integer number (163350).

2^2145771 is an apocalyptic number.

2145771 is a deficient number, since it is larger than the sum of its proper divisors (1121229).

2145771 is an equidigital number, since it uses as much as digits as its factorization.

2145771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520 (or 511 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 2145771 is about 1464.8450429994. The cubic root of 2145771 is about 128.9816090602.

It can be divided in two parts, 21457 and 71, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 2145771 in words is "two million, one hundred forty-five thousand, seven hundred seventy-one".