1142216821 has 4 divisors (see below), whose sum is σ = 1145065644. Its totient is φ = 1139368000.

The previous prime is 1142216819. The next prime is 1142216851. The reversal of 1142216821 is 1286122411.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1286122411 = 7 ⋅183731773.

It can be written as a sum of positive squares in 2 ways, for example, as 653364721 + 488852100 = 25561^2 + 22110^2 .

It is a cyclic number.

It is not a de Polignac number, because 1142216821 - 2¹ = 1142216819 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1142216821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1142216851) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1423810 + ... + 1424611.

It is an arithmetic number, because the mean of its divisors is an integer number (286266411).

Almost surely, 2^1142216821 is an apocalyptic number.

It is an amenable number.

1142216821 is a deficient number, since it is larger than the sum of its proper divisors (2848823).

1142216821 is an equidigital number, since it uses as much as digits as its factorization.

1142216821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2848822.

The product of its digits is 1536, while the sum is 28.

The square root of 1142216821 is about 33796.6983742495. The cubic root of 1142216821 is about 1045.3206195520.

The spelling of 1142216821 in words is "one billion, one hundred forty-two million, two hundred sixteen thousand, eight hundred twenty-one".