721143623 has 4 divisors (see below), whose sum is σ = 723108960. Its totient is φ = 719178288.

The previous prime is 721143571. The next prime is 721143637. The reversal of 721143623 is 326341127.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 721143623 - 2⁶ = 721143559 is a prime.

It is a super-2 number, since 2×721143623² = 1040096249987132258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721143023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 982118 + ... + 982851.

It is an arithmetic number, because the mean of its divisors is an integer number (180777240).

Almost surely, 2^721143623 is an apocalyptic number.

721143623 is a deficient number, since it is larger than the sum of its proper divisors (1965337).

721143623 is a wasteful number, since it uses less digits than its factorization.

721143623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1965336.

The product of its digits is 6048, while the sum is 29.

The square root of 721143623 is about 26854.1174310384. The cubic root of 721143623 is about 896.7552387980.

The spelling of 721143623 in words is "seven hundred twenty-one million, one hundred forty-three thousand, six hundred twenty-three".