138237511428 has 36 divisors (see below), whose sum is σ = 349455374268. Its totient is φ = 46076313600.

The previous prime is 138237511427. The next prime is 138237511439. The reversal of 138237511428 is 824115732831.

138237511428 is a `hidden beast` number, since 1 + 3 + 82 + 37 + 511 + 4 + 28 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 44737326144 + 93500185284 = 211512^2 + 305778^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (138237511427) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 516100 + ... + 736772.

Almost surely, 2^138237511428 is an apocalyptic number.

138237511428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138237511428 is an abundant number, since it is smaller than the sum of its proper divisors (211217862840).

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

138237511428 is a wasteful number, since it uses less digits than its factorization.

138237511428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238084 (or 238079 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The spelling of 138237511428 in words is "one hundred thirty-eight billion, two hundred thirty-seven million, five hundred eleven thousand, four hundred twenty-eight".