1143242721 has 8 divisors (see below), whose sum is σ = 1693692960. Its totient is φ = 762161796.

The previous prime is 1143242713. The next prime is 1143242731. The reversal of 1143242721 is 1272423411.

It is not a de Polignac number, because 1143242721 - 2³ = 1143242713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 42342323 = 1143242721 / (1 + 1 + 4 + 3 + 2 + 4 + 2 + 7 + 2 + 1).

It is not an unprimeable number, because it can be changed into a prime (1143242731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21171135 + ... + 21171188.

It is an arithmetic number, because the mean of its divisors is an integer number (211711620).

Almost surely, 2^1143242721 is an apocalyptic number.

It is an amenable number.

1143242721 is a deficient number, since it is larger than the sum of its proper divisors (550450239).

1143242721 is an equidigital number, since it uses as much as digits as its factorization.

1143242721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42342332 (or 42342326 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 1143242721 is about 33811.8724858592. The cubic root of 1143242721 is about 1045.6334829539.

The spelling of 1143242721 in words is "one billion, one hundred forty-three million, two hundred forty-two thousand, seven hundred twenty-one".