2156545 has 8 divisors (see below), whose sum is σ = 2658024. Its totient is φ = 1678464.

The previous prime is 2156537. The next prime is 2156597. The reversal of 2156545 is 5456512.

2156545 = T₁₃₉ + T₁₄₀ + ... + T₂₄₉.

It can be written as a sum of positive squares in 4 ways, for example, as 831744 + 1324801 = 912^2 + 1151^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2156545 - 2³ = 2156537 is a prime.

It is a Duffinian number.

2156545 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5644 + ... + 6013.

It is an arithmetic number, because the mean of its divisors is an integer number (332253).

It is a Proth number, since it is equal to 1053 ⋅ 2¹¹ + 1 and 1053 < 2¹¹.

2^2156545 is an apocalyptic number.

It is an amenable number.

2156545 is a deficient number, since it is larger than the sum of its proper divisors (501479).

2156545 is a wasteful number, since it uses less digits than its factorization.

2156545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11699.

The product of its digits is 6000, while the sum is 28.

The square root of 2156545 is about 1468.5179603941. The cubic root of 2156545 is about 129.1971226599.

It can be divided in two parts, 2156 and 545, that added together give a triangular number (2701 = T₇₃).

The spelling of 2156545 in words is "two million, one hundred fifty-six thousand, five hundred forty-five".