1221350401 has 4 divisors (see below), whose sum is σ = 1223204400. Its totient is φ = 1219496404.

The previous prime is 1221350387. The next prime is 1221350441. The reversal of 1221350401 is 1040531221.

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 1221350401 - 2²³ = 1212961793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221350441) 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, 926011 + ... + 927328.

It is an arithmetic number, because the mean of its divisors is an integer number (305801100).

Almost surely, 2^1221350401 is an apocalyptic number.

It is an amenable number.

1221350401 is a deficient number, since it is larger than the sum of its proper divisors (1853999).

1221350401 is an equidigital number, since it uses as much as digits as its factorization.

1221350401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1853998.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1221350401 is about 34947.8239809004. The cubic root of 1221350401 is about 1068.9238316658.

Adding to 1221350401 its reverse (1040531221), we get a palindrome (2261881622).

The spelling of 1221350401 in words is "one billion, two hundred twenty-one million, three hundred fifty thousand, four hundred one".