1221320031 has 8 divisors (see below), whose sum is σ = 1629962880. Its totient is φ = 813445272.

The previous prime is 1221320029. The next prime is 1221320041. The reversal of 1221320031 is 1300231221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221320031 - 2¹ = 1221320029 is a prime.

It is a super-2 number, since 2×1221320031² = 2983245236243681922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221320021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188301 + ... + 194678.

It is an arithmetic number, because the mean of its divisors is an integer number (203745360).

Almost surely, 2^1221320031 is an apocalyptic number.

1221320031 is a deficient number, since it is larger than the sum of its proper divisors (408642849).

1221320031 is a wasteful number, since it uses less digits than its factorization.

1221320031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384045.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1221320031 is about 34947.3894733212. The cubic root of 1221320031 is about 1068.9149716679.

Adding to 1221320031 its reverse (1300231221), we get a palindrome (2521551252).

The spelling of 1221320031 in words is "one billion, two hundred twenty-one million, three hundred twenty thousand, thirty-one".