1221751322677 has 4 divisors (see below), whose sum is σ = 1224424739596. Its totient is φ = 1219077905760.

The previous prime is 1221751322669. The next prime is 1221751322699. The reversal of 1221751322677 is 7762231571221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 726706805841 + 495044516836 = 852471^2 + 703594^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221751322677 - 2³ = 1221751322669 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 (1221751322657) 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, 1336707774 + ... + 1336708687.

It is an arithmetic number, because the mean of its divisors is an integer number (306106184899).

Almost surely, 2^{1221751322677} is an apocalyptic number.

It is an amenable number.

1221751322677 is a deficient number, since it is larger than the sum of its proper divisors (2673416919).

1221751322677 is an equidigital number, since it uses as much as digits as its factorization.

1221751322677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2673416918.

The product of its digits is 493920, while the sum is 46.

Adding to 1221751322677 its reverse (7762231571221), we get a palindrome (8983982893898).

The spelling of 1221751322677 in words is "one trillion, two hundred twenty-one billion, seven hundred fifty-one million, three hundred twenty-two thousand, six hundred seventy-seven".