138901554 has 80 divisors (see below), whose sum is σ = 354404160. Its totient is φ = 40249440.

The previous prime is 138901549. The next prime is 138901559. The reversal of 138901554 is 455109831.

138901554 is a `hidden beast` number, since 13 + 8 + 90 + 1 + 554 = 666.

It is an interprime number because it is at equal distance from previous prime (138901549) and next prime (138901559).

It is a super-2 number, since 2×138901554² = 38587283407229832, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138901559) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 39292 + ... + 42680.

It is an arithmetic number, because the mean of its divisors is an integer number (4430052).

Almost surely, 2^138901554 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138901554, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177202080).

138901554 is an abundant number, since it is smaller than the sum of its proper divisors (215502606).

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

138901554 is a wasteful number, since it uses less digits than its factorization.

138901554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3437 (or 3428 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 138901554 is about 11785.6503426837. The cubic root of 138901554 is about 517.8878252252.

The spelling of 138901554 in words is "one hundred thirty-eight million, nine hundred one thousand, five hundred fifty-four".