139692978 has 64 divisors (see below), whose sum is σ = 346032000. Its totient is φ = 41513472.

The previous prime is 139692953. The next prime is 139692979. The reversal of 139692978 is 879296931.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (139692979) 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 31 ways as a sum of consecutive naturals, for example, 13438 + ... + 21446.

It is an arithmetic number, because the mean of its divisors is an integer number (5406750).

Almost surely, 2^139692978 is an apocalyptic number.

139692978 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 139692978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (173016000).

139692978 is an abundant number, since it is smaller than the sum of its proper divisors (206339022).

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

139692978 is a wasteful number, since it uses less digits than its factorization.

139692978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8056 (or 8050 counting only the distinct ones).

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

The square root of 139692978 is about 11819.1783978414. The cubic root of 139692978 is about 518.8695585849.

The spelling of 139692978 in words is "one hundred thirty-nine million, six hundred ninety-two thousand, nine hundred seventy-eight".