399740543 has 4 divisors (see below), whose sum is σ = 400422120. Its totient is φ = 399058968.

The previous prime is 399740531. The next prime is 399740569. The reversal of 399740543 is 345047993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 345047993 = 769 ⋅448697.

It is a cyclic number.

It is not a de Polignac number, because 399740543 - 2⁶ = 399740479 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399740494 and 399740503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399740573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 339908 + ... + 341081.

It is an arithmetic number, because the mean of its divisors is an integer number (100105530).

Almost surely, 2^399740543 is an apocalyptic number.

399740543 is a deficient number, since it is larger than the sum of its proper divisors (681577).

399740543 is an equidigital number, since it uses as much as digits as its factorization.

399740543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681576.

The product of its (nonzero) digits is 408240, while the sum is 44.

The square root of 399740543 is about 19993.5125228160. The cubic root of 399740543 is about 736.6469573109.

The spelling of 399740543 in words is "three hundred ninety-nine million, seven hundred forty thousand, five hundred forty-three".