390878191 has 8 divisors (see below), whose sum is σ = 428327424. Its totient is φ = 353748120.

The previous prime is 390878149. The next prime is 390878197. The reversal of 390878191 is 191878093.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 390878191 - 2⁷ = 390878063 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 (390878197) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77221 + ... + 82126.

It is an arithmetic number, because the mean of its divisors is an integer number (53540928).

Almost surely, 2^390878191 is an apocalyptic number.

390878191 is a deficient number, since it is larger than the sum of its proper divisors (37449233).

390878191 is a wasteful number, since it uses less digits than its factorization.

390878191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159581.

The product of its (nonzero) digits is 108864, while the sum is 46.

The square root of 390878191 is about 19770.6396204068. The cubic root of 390878191 is about 731.1623385700.

It can be divided in two parts, 39087 and 8191, that added together give a triangular number (47278 = T₃₀₇).

The spelling of 390878191 in words is "three hundred ninety million, eight hundred seventy-eight thousand, one hundred ninety-one".