378873928921 has 4 divisors (see below), whose sum is σ = 382779845812. Its totient is φ = 374968012032.

The previous prime is 378873928913. The next prime is 378873928949. The reversal of 378873928921 is 129829378873.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 299230880400 + 79643048521 = 547020^2 + 282211^2 .

It is a cyclic number.

It is not a de Polignac number, because 378873928921 - 2³ = 378873928913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (378873920921) 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, 1952958300 + ... + 1952958493.

It is an arithmetic number, because the mean of its divisors is an integer number (95694961453).

Almost surely, 2^378873928921 is an apocalyptic number.

It is an amenable number.

378873928921 is a deficient number, since it is larger than the sum of its proper divisors (3905916891).

378873928921 is an equidigital number, since it uses as much as digits as its factorization.

378873928921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3905916890.

The product of its digits is 73156608, while the sum is 67.

The spelling of 378873928921 in words is "three hundred seventy-eight billion, eight hundred seventy-three million, nine hundred twenty-eight thousand, nine hundred twenty-one".