138868440 has 32 divisors (see below), whose sum is σ = 416605680. Its totient is φ = 37031552.

The previous prime is 138868439. The next prime is 138868441. The reversal of 138868440 is 44868831.

138868440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (138868439) and next prime (138868441).

It is a junction number, because it is equal to n+sod(n) for n = 138868392 and 138868401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138868441) 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, 578499 + ... + 578738.

Almost surely, 2^138868440 is an apocalyptic number.

138868440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138868440 is an abundant number, since it is smaller than the sum of its proper divisors (277737240).

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

138868440 is a wasteful number, since it uses less digits than its factorization.

138868440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157251 (or 1157247 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 42.

The square root of 138868440 is about 11784.2454149598. The cubic root of 138868440 is about 517.8466672973.

The spelling of 138868440 in words is "one hundred thirty-eight million, eight hundred sixty-eight thousand, four hundred forty".