138478464 has 128 divisors (see below), whose sum is σ = 432928800. Its totient is φ = 43425792.

The previous prime is 138478463. The next prime is 138478493. The reversal of 138478464 is 464874831.

138478464 is a `hidden beast` number, since 138 + 478 + 46 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138478463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57574 + ... + 59930.

Almost surely, 2^138478464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138478464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216464400).

138478464 is an abundant number, since it is smaller than the sum of its proper divisors (294450336).

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

138478464 is a wasteful number, since it uses less digits than its factorization.

138478464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2397 (or 2379 counting only the distinct ones).

The product of its digits is 516096, while the sum is 45.

The square root of 138478464 is about 11767.6872834045. The cubic root of 138478464 is about 517.3614668041.

The spelling of 138478464 in words is "one hundred thirty-eight million, four hundred seventy-eight thousand, four hundred sixty-four".