1251401040 has 240 divisors, whose sum is σ = 4412463120. Its totient is φ = 317399040.

The previous prime is 1251401027. The next prime is 1251401051. The reversal of 1251401040 is 401041521.

It can be written as a sum of positive squares in 8 ways, for example, as 25280784 + 1226120256 = 5028^2 + 35016^2 .

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 1523830 + ... + 1524650.

It is an arithmetic number, because the mean of its divisors is an integer number (18385263).

Almost surely, 2^1251401040 is an apocalyptic number.

1251401040 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 1251401040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2206231560).

1251401040 is an abundant number, since it is smaller than the sum of its proper divisors (3161062080).

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

1251401040 is a wasteful number, since it uses less digits than its factorization.

1251401040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942 (or 933 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1251401040 is about 35375.1472081743. The cubic root of 1251401040 is about 1077.6196546366.

Adding to 1251401040 its reverse (401041521), we get a palindrome (1652442561).

The spelling of 1251401040 in words is "one billion, two hundred fifty-one million, four hundred one thousand, forty".