1261056100 has 36 divisors (see below), whose sum is σ = 2750425524. Its totient is φ = 501854080.

The previous prime is 1261056077. The next prime is 1261056109. The reversal of 1261056100 is 16501621.

It can be written as a sum of positive squares in 6 ways, for example, as 360696064 + 900360036 = 18992^2 + 30006^2 .

It is not an unprimeable number, because it can be changed into a prime (1261056109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12307 + ... + 51706.

It is an arithmetic number, because the mean of its divisors is an integer number (76400709).

Almost surely, 2^1261056100 is an apocalyptic number.

1261056100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261056100 is an abundant number, since it is smaller than the sum of its proper divisors (1489369424).

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

1261056100 is a wasteful number, since it uses less digits than its factorization.

1261056100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64224 (or 64217 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1261056100 is about 35511.3517061798. The cubic root of 1261056100 is about 1080.3839798343.

Adding to 1261056100 its reverse (16501621), we get a palindrome (1277557721).

The spelling of 1261056100 in words is "one billion, two hundred sixty-one million, fifty-six thousand, one hundred".