1123251821 has 4 divisors (see below), whose sum is σ = 1124026332. Its totient is φ = 1122477312.

The previous prime is 1123251817. The next prime is 1123251841. The reversal of 1123251821 is 1281523211.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 703575625 + 419676196 = 26525^2 + 20486^2 .

It is a cyclic number.

It is not a de Polignac number, because 1123251821 - 2² = 1123251817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1123251841) 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, 385076 + ... + 387981.

It is an arithmetic number, because the mean of its divisors is an integer number (281006583).

Almost surely, 2^1123251821 is an apocalyptic number.

It is an amenable number.

1123251821 is a deficient number, since it is larger than the sum of its proper divisors (774511).

1123251821 is an equidigital number, since it uses as much as digits as its factorization.

1123251821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 774510.

The product of its digits is 960, while the sum is 26.

The square root of 1123251821 is about 33514.9492167301. The cubic root of 1123251821 is about 1039.5029124085.

The spelling of 1123251821 in words is "one billion, one hundred twenty-three million, two hundred fifty-one thousand, eight hundred twenty-one".