1978071243 has 4 divisors (see below), whose sum is σ = 2637428328. Its totient is φ = 1318714160.

The previous prime is 1978071241. The next prime is 1978071253. The reversal of 1978071243 is 3421708791.

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 1978071243 - 2¹ = 1978071241 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1978071195 and 1978071204.

It is not an unprimeable number, because it can be changed into a prime (1978071241) 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, 329678538 + ... + 329678543.

It is an arithmetic number, because the mean of its divisors is an integer number (659357082).

Almost surely, 2^1978071243 is an apocalyptic number.

1978071243 is a deficient number, since it is larger than the sum of its proper divisors (659357085).

1978071243 is an equidigital number, since it uses as much as digits as its factorization.

1978071243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659357084.

The product of its (nonzero) digits is 84672, while the sum is 42.

The square root of 1978071243 is about 44475.5128469588. The cubic root of 1978071243 is about 1255.2993667936.

The spelling of 1978071243 in words is "one billion, nine hundred seventy-eight million, seventy-one thousand, two hundred forty-three".