978381391 has 12 divisors (see below), whose sum is σ = 1064844792. Its totient is φ = 898506336.

The previous prime is 978381373. The next prime is 978381403. The reversal of 978381391 is 193183879.

It is not a de Polignac number, because 978381391 - 2¹³ = 978373199 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 (978381191) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18600 + ... + 47986.

It is an arithmetic number, because the mean of its divisors is an integer number (88737066).

Almost surely, 2^978381391 is an apocalyptic number.

978381391 is a deficient number, since it is larger than the sum of its proper divisors (86463401).

978381391 is a wasteful number, since it uses less digits than its factorization.

978381391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29610 (or 29597 counting only the distinct ones).

The product of its digits is 326592, while the sum is 49.

The square root of 978381391 is about 31279.0887175442. The cubic root of 978381391 is about 992.7412348153.

The spelling of 978381391 in words is "nine hundred seventy-eight million, three hundred eighty-one thousand, three hundred ninety-one".