391678051 has 4 divisors (see below), whose sum is σ = 391720032. Its totient is φ = 391636072.

The previous prime is 391678019. The next prime is 391678057. The reversal of 391678051 is 150876193.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 391678051 - 2⁵ = 391678019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 391677995 and 391678013.

It is not an unprimeable number, because it can be changed into a prime (391678057) 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, 6 + ... + 27988.

It is an arithmetic number, because the mean of its divisors is an integer number (97930008).

Almost surely, 2^391678051 is an apocalyptic number.

391678051 is a deficient number, since it is larger than the sum of its proper divisors (41981).

391678051 is a wasteful number, since it uses less digits than its factorization.

391678051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41980.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 391678051 is about 19790.8577631188. The cubic root of 391678051 is about 731.6607283162.

The spelling of 391678051 in words is "three hundred ninety-one million, six hundred seventy-eight thousand, fifty-one".