2121554 has 4 divisors (see below), whose sum is σ = 3182334. Its totient is φ = 1060776.

The previous prime is 2121529. The next prime is 2121569. The reversal of 2121554 is 4551212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1151329 + 970225 = 1073^2 + 985^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 530387 + ... + 530390.

2^2121554 is an apocalyptic number.

2121554 is a deficient number, since it is larger than the sum of its proper divisors (1060780).

2121554 is a wasteful number, since it uses less digits than its factorization.

2121554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060779.

The product of its digits is 400, while the sum is 20.

The square root of 2121554 is about 1456.5555258898. Note that the first 4 decimals coincide. The cubic root of 2121554 is about 128.4945467463.

Adding to 2121554 its reverse (4551212), we get a palindrome (6672766).

The spelling of 2121554 in words is "two million, one hundred twenty-one thousand, five hundred fifty-four".