1978724543 has 4 divisors (see below), whose sum is σ = 2082867960. Its totient is φ = 1874581128.

The previous prime is 1978724521. The next prime is 1978724551. The reversal of 1978724543 is 3454278791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3454278791 = 55663 ⋅62057.

It is a cyclic number.

It is not a de Polignac number, because 1978724543 - 2²⁶ = 1911615679 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1978724491 and 1978724500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978724563) 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, 52071680 + ... + 52071717.

It is an arithmetic number, because the mean of its divisors is an integer number (520716990).

Almost surely, 2^1978724543 is an apocalyptic number.

1978724543 is a deficient number, since it is larger than the sum of its proper divisors (104143417).

1978724543 is a wasteful number, since it uses less digits than its factorization.

1978724543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104143416.

The product of its digits is 1693440, while the sum is 50.

The square root of 1978724543 is about 44482.8567315545. The cubic root of 1978724543 is about 1255.4375479995.

The spelling of 1978724543 in words is "one billion, nine hundred seventy-eight million, seven hundred twenty-four thousand, five hundred forty-three".