399097378 has 4 divisors (see below), whose sum is σ = 598646070. Its totient is φ = 199548688.

The previous prime is 399097343. The next prime is 399097409. The reversal of 399097378 is 873790993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 873790993 = 12907 ⋅67699.

It can be written as a sum of positive squares in only one way, i.e., 300432889 + 98664489 = 17333^2 + 9933^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99774343 + ... + 99774346.

Almost surely, 2^399097378 is an apocalyptic number.

399097378 is a deficient number, since it is larger than the sum of its proper divisors (199548692).

399097378 is a wasteful number, since it uses less digits than its factorization.

399097378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199548691.

The product of its (nonzero) digits is 2571912, while the sum is 55.

The square root of 399097378 is about 19977.4217055155. The cubic root of 399097378 is about 736.2516676862.

The spelling of 399097378 in words is "three hundred ninety-nine million, ninety-seven thousand, three hundred seventy-eight".