1221504049 has 4 divisors (see below), whose sum is σ = 1222794864. Its totient is φ = 1220213236.

The previous prime is 1221504047. The next prime is 1221504073. The reversal of 1221504049 is 9404051221.

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 1221504049 - 2¹ = 1221504047 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221504047) 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, 643987 + ... + 645880.

It is an arithmetic number, because the mean of its divisors is an integer number (305698716).

Almost surely, 2^1221504049 is an apocalyptic number.

It is an amenable number.

1221504049 is a deficient number, since it is larger than the sum of its proper divisors (1290815).

1221504049 is an equidigital number, since it uses as much as digits as its factorization.

1221504049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1290814.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 1221504049 is about 34950.0221602219. The cubic root of 1221504049 is about 1068.9686539439.

The spelling of 1221504049 in words is "one billion, two hundred twenty-one million, five hundred four thousand, forty-nine".