67128138 has 216 divisors, whose sum is σ = 202230756. Its totient is φ = 15966720.

The previous prime is 67128091. The next prime is 67128151. The reversal of 67128138 is 83182176.

It can be written as a sum of positive squares in 2 ways, for example, as 58110129 + 9018009 = 7623^2 + 3003^2 .

It is a super-2 number, since 2×67128138² = 9012373822694088, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 1814256 + ... + 1814292.

Almost surely, 2^67128138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 67128138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101115378).

67128138 is an abundant number, since it is smaller than the sum of its proper divisors (135102618).

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

67128138 is a wasteful number, since it uses less digits than its factorization.

67128138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 77 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 67128138 is about 8193.1763071473. The cubic root of 67128138 is about 406.4135698563.

The spelling of 67128138 in words is "sixty-seven million, one hundred twenty-eight thousand, one hundred thirty-eight".