2151021 has 8 divisors (see below), whose sum is σ = 2895264. Its totient is φ = 1420400.

The previous prime is 2151013. The next prime is 2151031. The reversal of 2151021 is 1201512.

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 2151021 - 2³ = 2151013 is a prime.

It is a Curzon number.

2151021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2150988 and 2151006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151001) 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, 3030 + ... + 3671.

It is an arithmetic number, because the mean of its divisors is an integer number (361908).

2^2151021 is an apocalyptic number.

It is an amenable number.

2151021 is a deficient number, since it is larger than the sum of its proper divisors (744243).

2151021 is a wasteful number, since it uses less digits than its factorization.

2151021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6811.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 2151021 is about 1466.6359466480. The cubic root of 2151021 is about 129.0867153273.

Adding to 2151021 its reverse (1201512), we get a palindrome (3352533).

The spelling of 2151021 in words is "two million, one hundred fifty-one thousand, twenty-one".