2151775 has 24 divisors (see below), whose sum is σ = 2906064. Its totient is φ = 1574400.

The previous prime is 2151767. The next prime is 2151781. The reversal of 2151775 is 5771512.

2151775 is a nontrivial binomial coefficient, being equal to C(2075, 2).

It is not a de Polignac number, because 2151775 - 2³ = 2151767 is a prime.

It is a Duffinian number.

2151775 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25884 + ... + 25966.

It is an arithmetic number, because the mean of its divisors is an integer number (121086).

2^2151775 is an apocalyptic number.

2151775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2151775 is the 2074-th triangular number.

2151775 is the 692-nd centered nonagonal number.

2151775 is a deficient number, since it is larger than the sum of its proper divisors (754289).

2151775 is a wasteful number, since it uses less digits than its factorization.

2151775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 166 counting only the distinct ones).

The product of its digits is 2450, while the sum is 28.

The square root of 2151775 is about 1466.8929749644. The cubic root of 2151775 is about 129.1017965395.

It can be divided in two parts, 2151 and 775, that added together give a triangular number (2926 = T₇₆).

The spelling of 2151775 in words is "two million, one hundred fifty-one thousand, seven hundred seventy-five".