2121557 has 4 divisors (see below), whose sum is σ = 2136960. Its totient is φ = 2106156.

The previous prime is 2121529. The next prime is 2121569. The reversal of 2121557 is 7551212.

It is a happy number.

2121557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2121557 - 2¹² = 2117461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7493 + ... + 7770.

It is an arithmetic number, because the mean of its divisors is an integer number (534240).

2^2121557 is an apocalyptic number.

It is an amenable number.

2121557 is a deficient number, since it is larger than the sum of its proper divisors (15403).

2121557 is a wasteful number, since it uses less digits than its factorization.

2121557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15402.

The product of its digits is 700, while the sum is 23.

The square root of 2121557 is about 1456.5565557163. The cubic root of 2121557 is about 128.4946073125.

Adding to 2121557 its reverse (7551212), we get a palindrome (9672769).

The spelling of 2121557 in words is "two million, one hundred twenty-one thousand, five hundred fifty-seven".