1251840 has 80 divisors (see below), whose sum is σ = 4026528. Its totient is φ = 331776.

The previous prime is 1251827. The next prime is 1251841. The reversal of 1251840 is 481521.

1251840 is nontrivially palindromic in base 11.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (1251841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7599 + ... + 7761.

2^1251840 is an apocalyptic number.

1251840 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 1251840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2013264).

1251840 is an abundant number, since it is smaller than the sum of its proper divisors (2774688).

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

1251840 is an equidigital number, since it uses as much as digits as its factorization.

1251840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 1251840 is about 1118.8565591710. The cubic root of 1251840 is about 107.7745640528.

The spelling of 1251840 in words is "one million, two hundred fifty-one thousand, eight hundred forty".