2155021 has 8 divisors (see below), whose sum is σ = 2361600. Its totient is φ = 1950240.

The previous prime is 2155009. The next prime is 2155057. The reversal of 2155021 is 1205512.

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 2155021 - 2¹¹ = 2152973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2154986 and 2155004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4260 + ... + 4738.

It is an arithmetic number, because the mean of its divisors is an integer number (295200).

2^2155021 is an apocalyptic number.

It is an amenable number.

2155021 is a deficient number, since it is larger than the sum of its proper divisors (206579).

2155021 is a wasteful number, since it uses less digits than its factorization.

2155021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 2155021 is about 1467.9989782013. The cubic root of 2155021 is about 129.1666815586.

The spelling of 2155021 in words is "two million, one hundred fifty-five thousand, twenty-one".