7878121861983 has 4 divisors (see below), whose sum is σ = 10504162482648. Its totient is φ = 5252081241320.

The previous prime is 7878121861949. The next prime is 7878121861999. The reversal of 7878121861983 is 3891681218787.

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 7878121861983 - 2¹⁴ = 7878121845599 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7878121861903) 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, 1313020310328 + ... + 1313020310333.

It is an arithmetic number, because the mean of its divisors is an integer number (2626040620662).

Almost surely, 2^{7878121861983} is an apocalyptic number.

7878121861983 is a deficient number, since it is larger than the sum of its proper divisors (2626040620665).

7878121861983 is a wasteful number, since it uses less digits than its factorization.

7878121861983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2626040620664.

The product of its digits is 65028096, while the sum is 69.

The spelling of 7878121861983 in words is "seven trillion, eight hundred seventy-eight billion, one hundred twenty-one million, eight hundred sixty-one thousand, nine hundred eighty-three".