1331551 has 6 divisors (see below), whose sum is σ = 1442040. Its totient is φ = 1228968.

The previous prime is 1331549. The next prime is 1331567. The reversal of 1331551 is 1551331.

It is not a de Polignac number, because 1331551 - 2¹ = 1331549 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 (1331521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3771 + ... + 4108.

It is an arithmetic number, because the mean of its divisors is an integer number (240340).

2^1331551 is an apocalyptic number.

1331551 is a deficient number, since it is larger than the sum of its proper divisors (110489).

1331551 is an equidigital number, since it uses as much as digits as its factorization.

1331551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7905 (or 7892 counting only the distinct ones).

The product of its digits is 225, while the sum is 19.

The square root of 1331551 is about 1153.9285073175. The cubic root of 1331551 is about 110.0151769693.

Adding to 1331551 its reverse (1551331), we get a palindrome (2882882).

It can be divided in two parts, 13315 and 51, that added together give a triangular number (13366 = T₁₆₃).

The spelling of 1331551 in words is "one million, three hundred thirty-one thousand, five hundred fifty-one".