1221342131 has 4 divisors (see below), whose sum is σ = 1221417000. Its totient is φ = 1221267264.

The previous prime is 1221342127. The next prime is 1221342167. The reversal of 1221342131 is 1312431221.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1221342131 - 2² = 1221342127 is a prime.

It is a super-2 number, since 2×1221342131² = 2983353201911242322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221342181) 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, 1406 + ... + 49443.

It is an arithmetic number, because the mean of its divisors is an integer number (305354250).

Almost surely, 2^1221342131 is an apocalyptic number.

1221342131 is a deficient number, since it is larger than the sum of its proper divisors (74869).

1221342131 is an equidigital number, since it uses as much as digits as its factorization.

1221342131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74868.

The product of its digits is 288, while the sum is 20.

The square root of 1221342131 is about 34947.7056614594. The cubic root of 1221342131 is about 1068.9214190303.

Adding to 1221342131 its reverse (1312431221), we get a palindrome (2533773352).

The spelling of 1221342131 in words is "one billion, two hundred twenty-one million, three hundred forty-two thousand, one hundred thirty-one".