1396920978 has 48 divisors (see below), whose sum is σ = 3145484160. Its totient is φ = 464643216.

The previous prime is 1396920961. The next prime is 1396920997. The reversal of 1396920978 is 8790296931.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 244551 + ... + 250197.

It is an arithmetic number, because the mean of its divisors is an integer number (65530920).

Almost surely, 2^1396920978 is an apocalyptic number.

1396920978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1396920978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1572742080).

1396920978 is an abundant number, since it is smaller than the sum of its proper divisors (1748563182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1396920978 is an equidigital number, since it uses as much as digits as its factorization.

1396920978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6173 (or 6161 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The square root of 1396920978 is about 37375.4060579949. The cubic root of 1396920978 is about 1117.8682287255.

The spelling of 1396920978 in words is "one billion, three hundred ninety-six million, nine hundred twenty thousand, nine hundred seventy-eight".