1261422240 has 192 divisors, whose sum is σ = 4417846272. Its totient is φ = 300441600.

The previous prime is 1261422223. The next prime is 1261422247. The reversal of 1261422240 is 422241621.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1261422240.

It is not an unprimeable number, because it can be changed into a prime (1261422247) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 190180 + ... + 196700.

It is an arithmetic number, because the mean of its divisors is an integer number (23009616).

Almost surely, 2^1261422240 is an apocalyptic number.

1261422240 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 1261422240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2208923136).

1261422240 is an abundant number, since it is smaller than the sum of its proper divisors (3156424032).

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

1261422240 is a wasteful number, since it uses less digits than its factorization.

1261422240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6583 (or 6575 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 1261422240 is about 35516.5065849669. The cubic root of 1261422240 is about 1080.4885306978.

Adding to 1261422240 its reverse (422241621), we get a palindrome (1683663861).

The spelling of 1261422240 in words is "one billion, two hundred sixty-one million, four hundred twenty-two thousand, two hundred forty".