1251705 has 48 divisors (see below), whose sum is σ = 2528064. Its totient is φ = 524160.

The previous prime is 1251703. The next prime is 1251707. The reversal of 1251705 is 5071521.

It is an interprime number because it is at equal distance from previous prime (1251703) and next prime (1251707).

It is not a de Polignac number, because 1251705 - 2¹ = 1251703 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1251703) 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 47 ways as a sum of consecutive naturals, for example, 9490 + ... + 9620.

It is an arithmetic number, because the mean of its divisors is an integer number (52668).

2^1251705 is an apocalyptic number.

1251705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1251705 is an abundant number, since it is smaller than the sum of its proper divisors (1276359).

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

1251705 is a wasteful number, since it uses less digits than its factorization.

1251705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 350, while the sum is 21.

The square root of 1251705 is about 1118.7962280952. The cubic root of 1251705 is about 107.7706897320.

It can be divided in two parts, 125 and 1705, that added together give a triangular number (1830 = T₆₀).

The spelling of 1251705 in words is "one million, two hundred fifty-one thousand, seven hundred five".