1242224021 has 4 divisors (see below), whose sum is σ = 1249164000. Its totient is φ = 1235284044.

The previous prime is 1242224003. The next prime is 1242224041. The reversal of 1242224021 is 1204222421.

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 a de Polignac number, because none of the positive numbers 2^k-1242224021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1242223984 and 1242224002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242224041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3469721 + ... + 3470078.

It is an arithmetic number, because the mean of its divisors is an integer number (312291000).

Almost surely, 2^1242224021 is an apocalyptic number.

It is an amenable number.

1242224021 is a deficient number, since it is larger than the sum of its proper divisors (6939979).

1242224021 is an equidigital number, since it uses as much as digits as its factorization.

1242224021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6939978.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 1242224021 is about 35245.1985524270. The cubic root of 1242224021 is about 1074.9789852752.

Adding to 1242224021 its reverse (1204222421), we get a palindrome (2446446442).

The spelling of 1242224021 in words is "one billion, two hundred forty-two million, two hundred twenty-four thousand, twenty-one".