143999721 has 16 divisors (see below), whose sum is σ = 213624000. Its totient is φ = 95868864.

The previous prime is 143999717. The next prime is 143999729. The reversal of 143999721 is 127999341.

It is not a de Polignac number, because 143999721 - 2² = 143999717 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (143999729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19105 + ... + 25553.

It is an arithmetic number, because the mean of its divisors is an integer number (13351500).

Almost surely, 2^143999721 is an apocalyptic number.

It is an amenable number.

143999721 is a deficient number, since it is larger than the sum of its proper divisors (69624279).

143999721 is an equidigital number, since it uses as much as digits as its factorization.

143999721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7285 (or 7279 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 143999721 is about 11999.9883749944. The cubic root of 143999721 is about 524.1479403291.

The spelling of 143999721 in words is "one hundred forty-three million, nine hundred ninety-nine thousand, seven hundred twenty-one".