378133721 has 4 divisors (see below), whose sum is σ = 432152832. Its totient is φ = 324114612.

The previous prime is 378133711. The next prime is 378133751. The reversal of 378133721 is 127331873.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-378133721 is a prime.

It is a super-2 number, since 2×378133721² = 285970221914611682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (378133711) 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, 27009545 + ... + 27009558.

It is an arithmetic number, because the mean of its divisors is an integer number (108038208).

Almost surely, 2^378133721 is an apocalyptic number.

It is an amenable number.

378133721 is a deficient number, since it is larger than the sum of its proper divisors (54019111).

378133721 is an equidigital number, since it uses as much as digits as its factorization.

378133721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54019110.

The product of its digits is 21168, while the sum is 35.

The square root of 378133721 is about 19445.6607241821. The cubic root of 378133721 is about 723.1279302148.

The spelling of 378133721 in words is "three hundred seventy-eight million, one hundred thirty-three thousand, seven hundred twenty-one".