378729221 has 4 divisors (see below), whose sum is σ = 407862252. Its totient is φ = 349596192.

The previous prime is 378729217. The next prime is 378729229. The reversal of 378729221 is 122927873.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122927873 = 347 ⋅354259.

It can be written as a sum of positive squares in 2 ways, for example, as 85840225 + 292888996 = 9265^2 + 17114^2 .

It is a cyclic number.

It is not a de Polignac number, because 378729221 - 2² = 378729217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (378729229) 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, 14566496 + ... + 14566521.

It is an arithmetic number, because the mean of its divisors is an integer number (101965563).

Almost surely, 2^378729221 is an apocalyptic number.

It is an amenable number.

378729221 is a deficient number, since it is larger than the sum of its proper divisors (29133031).

378729221 is a wasteful number, since it uses less digits than its factorization.

378729221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29133030.

The product of its digits is 84672, while the sum is 41.

The square root of 378729221 is about 19460.9665998377. The cubic root of 378729221 is about 723.5073346443.

The spelling of 378729221 in words is "three hundred seventy-eight million, seven hundred twenty-nine thousand, two hundred twenty-one".