1224540021 has 32 divisors (see below), whose sum is σ = 1727889408. Its totient is φ = 770238720.

The previous prime is 1224540019. The next prime is 1224540061. The reversal of 1224540021 is 1200454221.

It is not a de Polignac number, because 1224540021 - 2¹ = 1224540019 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1224540021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1224540011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1892320 + ... + 1892966.

It is an arithmetic number, because the mean of its divisors is an integer number (53996544).

Almost surely, 2^1224540021 is an apocalyptic number.

It is an amenable number.

1224540021 is a deficient number, since it is larger than the sum of its proper divisors (503349387).

1224540021 is a wasteful number, since it uses less digits than its factorization.

1224540021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161.

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 1224540021 is about 34993.4282544594. The cubic root of 1224540021 is about 1069.8535395075.

Adding to 1224540021 its reverse (1200454221), we get a palindrome (2424994242).

The spelling of 1224540021 in words is "one billion, two hundred twenty-four million, five hundred forty thousand, twenty-one".