1351665 has 36 divisors (see below), whose sum is σ = 2729844. Its totient is φ = 616896.

The previous prime is 1351663. The next prime is 1351667. The reversal of 1351665 is 5661531.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1351663) and next prime (1351667).

It can be written as a sum of positive squares in 2 ways, for example, as 159201 + 1192464 = 399^2 + 1092^2 .

It is not a de Polignac number, because 1351665 - 2¹ = 1351663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1351663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1899 + ... + 2511.

It is an arithmetic number, because the mean of its divisors is an integer number (75829).

2^1351665 is an apocalyptic number.

1351665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1351665 is an abundant number, since it is smaller than the sum of its proper divisors (1378179).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1351665 is a wasteful number, since it uses less digits than its factorization.

1351665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638 (or 628 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The square root of 1351665 is about 1162.6112849960. The cubic root of 1351665 is about 110.5663626811.

It can be divided in two parts, 1351 and 665, that added together give a triangular number (2016 = T₆₃).

The spelling of 1351665 in words is "one million, three hundred fifty-one thousand, six hundred sixty-five".