1261100544 has 160 divisors (see below), whose sum is σ = 3706369920. Its totient is φ = 377856000.

The previous prime is 1261100539. The next prime is 1261100593. The reversal of 1261100544 is 4450011621.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1706127 + ... + 1706865.

It is an arithmetic number, because the mean of its divisors is an integer number (23164812).

Almost surely, 2^1261100544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261100544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1853184960).

1261100544 is an abundant number, since it is smaller than the sum of its proper divisors (2445269376).

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

1261100544 is a wasteful number, since it uses less digits than its factorization.

1261100544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872 (or 856 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 1261100544 is about 35511.9774723965. The cubic root of 1261100544 is about 1080.3966718474.

The spelling of 1261100544 in words is "one billion, two hundred sixty-one million, one hundred thousand, five hundred forty-four".