1121644261 has 4 divisors (see below), whose sum is σ = 1122065932. Its totient is φ = 1121222592.

The previous prime is 1121644259. The next prime is 1121644273. The reversal of 1121644261 is 1624461211.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1624461211 = 18269 ⋅88919.

It can be written as a sum of positive squares in 2 ways, for example, as 144144036 + 977500225 = 12006^2 + 31265^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121644261 - 2¹ = 1121644259 is a prime.

It is a super-3 number, since 3×1121644261³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121642261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206820 + ... + 212173.

It is an arithmetic number, because the mean of its divisors is an integer number (280516483).

Almost surely, 2^1121644261 is an apocalyptic number.

It is an amenable number.

1121644261 is a deficient number, since it is larger than the sum of its proper divisors (421671).

1121644261 is an equidigital number, since it uses as much as digits as its factorization.

1121644261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421670.

The product of its digits is 2304, while the sum is 28.

The square root of 1121644261 is about 33490.9578991106. The cubic root of 1121644261 is about 1039.0067751830.

The spelling of 1121644261 in words is "one billion, one hundred twenty-one million, six hundred forty-four thousand, two hundred sixty-one".