1331223551 has 4 divisors (see below), whose sum is σ = 1521398352. Its totient is φ = 1141048752.

The previous prime is 1331223503. The next prime is 1331223559. The reversal of 1331223551 is 1553221331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1553221331 = 2927 ⋅530653.

It is a cyclic number.

It is not a de Polignac number, because 1331223551 - 2¹⁴ = 1331207167 is a prime.

It is a super-2 number, since 2×1331223551² = 3544312285474099202, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1331223551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331223559) 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, 95087390 + ... + 95087403.

It is an arithmetic number, because the mean of its divisors is an integer number (380349588).

Almost surely, 2^1331223551 is an apocalyptic number.

1331223551 is a deficient number, since it is larger than the sum of its proper divisors (190174801).

1331223551 is an equidigital number, since it uses as much as digits as its factorization.

1331223551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190174800.

The product of its digits is 2700, while the sum is 26.

The square root of 1331223551 is about 36485.9363453920. The cubic root of 1331223551 is about 1100.0615808500.

Adding to 1331223551 its reverse (1553221331), we get a palindrome (2884444882).

It can be divided in two parts, 13312 and 23551, that added together give a palindrome (36863).

The spelling of 1331223551 in words is "one billion, three hundred thirty-one million, two hundred twenty-three thousand, five hundred fifty-one".