378291981 has 4 divisors (see below), whose sum is σ = 504389312. Its totient is φ = 252194652.

The previous prime is 378291961. The next prime is 378291989. The reversal of 378291981 is 189192873.

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 not a de Polignac number, because 378291981 - 2⁶ = 378291917 is a prime.

It is a super-2 number, since 2×378291981² = 286209645777808722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 378291981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (378291989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63048661 + ... + 63048666.

It is an arithmetic number, because the mean of its divisors is an integer number (126097328).

Almost surely, 2^378291981 is an apocalyptic number.

It is an amenable number.

378291981 is a deficient number, since it is larger than the sum of its proper divisors (126097331).

378291981 is a wasteful number, since it uses less digits than its factorization.

378291981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126097330.

The product of its digits is 217728, while the sum is 48.

The square root of 378291981 is about 19449.7295868092. The cubic root of 378291981 is about 723.2287995262.

The spelling of 378291981 in words is "three hundred seventy-eight million, two hundred ninety-one thousand, nine hundred eighty-one".