2155641 has 4 divisors (see below), whose sum is σ = 2874192. Its totient is φ = 1437092.

The previous prime is 2155639. The next prime is 2155661. The reversal of 2155641 is 1465512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2155641 - 2¹ = 2155639 is a prime.

It is a D-number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2155661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359271 + ... + 359276.

It is an arithmetic number, because the mean of its divisors is an integer number (718548).

2^2155641 is an apocalyptic number.

It is an amenable number.

2155641 is a deficient number, since it is larger than the sum of its proper divisors (718551).

2155641 is an equidigital number, since it uses as much as digits as its factorization.

2155641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718550.

The product of its digits is 1200, while the sum is 24.

The square root of 2155641 is about 1468.2101348240. The cubic root of 2155641 is about 129.1790674647.

The spelling of 2155641 in words is "two million, one hundred fifty-five thousand, six hundred forty-one".