138900040 has 32 divisors (see below), whose sum is σ = 319178880. Its totient is φ = 54377152.

The previous prime is 138900037. The next prime is 138900043. The reversal of 138900040 is 40009831.

It is an interprime number because it is at equal distance from previous prime (138900037) and next prime (138900043).

It is a super-2 number, since 2×138900040² = 38586442224003200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138899978 and 138900014.

It is not an unprimeable number, because it can be changed into a prime (138900043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35062 + ... + 38821.

It is an arithmetic number, because the mean of its divisors is an integer number (9974340).

Almost surely, 2^138900040 is an apocalyptic number.

138900040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138900040 is an abundant number, since it is smaller than the sum of its proper divisors (180278840).

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

138900040 is a wasteful number, since it uses less digits than its factorization.

138900040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73941 (or 73937 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 138900040 is about 11785.5861118571. The cubic root of 138900040 is about 517.8859435927.

Adding to 138900040 its reverse (40009831), we get a palindrome (178909871).

The spelling of 138900040 in words is "one hundred thirty-eight million, nine hundred thousand, forty".