1221042413 has 4 divisors (see below), whose sum is σ = 1221312288. Its totient is φ = 1220772540.

The previous prime is 1221042373. The next prime is 1221042437. The reversal of 1221042413 is 3142401221.

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 1221042413 - 2²² = 1216848109 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 (1221042463) 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, 128033 + ... + 137238.

It is an arithmetic number, because the mean of its divisors is an integer number (305328072).

Almost surely, 2^1221042413 is an apocalyptic number.

It is an amenable number.

1221042413 is a deficient number, since it is larger than the sum of its proper divisors (269875).

1221042413 is an equidigital number, since it uses as much as digits as its factorization.

1221042413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269874.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1221042413 is about 34943.4173056958. The cubic root of 1221042413 is about 1068.8339739178.

Adding to 1221042413 its reverse (3142401221), we get a palindrome (4363443634).

The spelling of 1221042413 in words is "one billion, two hundred twenty-one million, forty-two thousand, four hundred thirteen".