691389143 has 8 divisors (see below), whose sum is σ = 699099648. Its totient is φ = 683714304.

The previous prime is 691389107. The next prime is 691389151. The reversal of 691389143 is 341983196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691389143 - 2¹⁸ = 691126999 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 691389094 and 691389103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691382143) 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, 31055 + ... + 48447.

It is an arithmetic number, because the mean of its divisors is an integer number (87387456).

Almost surely, 2^691389143 is an apocalyptic number.

691389143 is a deficient number, since it is larger than the sum of its proper divisors (7710505).

691389143 is a wasteful number, since it uses less digits than its factorization.

691389143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17833.

The product of its digits is 139968, while the sum is 44.

The square root of 691389143 is about 26294.2796630750. The cubic root of 691389143 is about 884.2482014816.

The spelling of 691389143 in words is "six hundred ninety-one million, three hundred eighty-nine thousand, one hundred forty-three".