128121738 has 16 divisors (see below), whose sum is σ = 256426560. Its totient is φ = 42676736.

The previous prime is 128121733. The next prime is 128121767. The reversal of 128121738 is 837121821.

It is a junction number, because it is equal to n+sod(n) for n = 128121699 and 128121708.

It is not an unprimeable number, because it can be changed into a prime (128121733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2506 + ... + 16202.

It is an arithmetic number, because the mean of its divisors is an integer number (16026660).

Almost surely, 2^128121738 is an apocalyptic number.

128121738 is an abundant number, since it is smaller than the sum of its proper divisors (128304822).

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

128121738 is a wasteful number, since it uses less digits than its factorization.

128121738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15261.

The product of its digits is 5376, while the sum is 33.

The square root of 128121738 is about 11319.0873306994. The cubic root of 128121738 is about 504.1281404464.

The spelling of 128121738 in words is "one hundred twenty-eight million, one hundred twenty-one thousand, seven hundred thirty-eight".