1251540 has 72 divisors (see below), whose sum is σ = 4029480. Its totient is φ = 313344.

The previous prime is 1251533. The next prime is 1251571. The reversal of 1251540 is 451521.

1251540 is a `hidden beast` number, since 125 + 1 + 540 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 535824 + 715716 = 732^2 + 846^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2856 + ... + 3264.

It is an arithmetic number, because the mean of its divisors is an integer number (55965).

2^1251540 is an apocalyptic number.

1251540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1251540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2014740).

1251540 is an abundant number, since it is smaller than the sum of its proper divisors (2777940).

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

1251540 is a wasteful number, since it uses less digits than its factorization.

1251540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 436 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 1251540 is about 1118.7224856952. The cubic root of 1251540 is about 107.7659540727.

The spelling of 1251540 in words is "one million, two hundred fifty-one thousand, five hundred forty".