1221260277 has 4 divisors (see below), whose sum is σ = 1628347040. Its totient is φ = 814173516.

The previous prime is 1221260239. The next prime is 1221260323. The reversal of 1221260277 is 7720621221.

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 not a de Polignac number, because 1221260277 - 2¹⁰ = 1221259253 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 (1221260177) 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, 203543377 + ... + 203543382.

It is an arithmetic number, because the mean of its divisors is an integer number (407086760).

Almost surely, 2^1221260277 is an apocalyptic number.

It is an amenable number.

1221260277 is a deficient number, since it is larger than the sum of its proper divisors (407086763).

1221260277 is an equidigital number, since it uses as much as digits as its factorization.

1221260277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407086762.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 1221260277 is about 34946.5345492225. The cubic root of 1221260277 is about 1068.8975388943.

Adding to 1221260277 its reverse (7720621221), we get a palindrome (8941881498).

The spelling of 1221260277 in words is "one billion, two hundred twenty-one million, two hundred sixty thousand, two hundred seventy-seven".