128421437 has 16 divisors (see below), whose sum is σ = 142540800. Its totient is φ = 115207920.

The previous prime is 128421431. The next prime is 128421457. The reversal of 128421437 is 734124821.

It is a cyclic number.

It is not a de Polignac number, because 128421437 - 2¹⁸ = 128159293 is a prime.

It is a super-2 number, since 2×128421437² = 32984130962289938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128421431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25364 + ... + 30002.

It is an arithmetic number, because the mean of its divisors is an integer number (8908800).

Almost surely, 2^128421437 is an apocalyptic number.

It is an amenable number.

128421437 is a deficient number, since it is larger than the sum of its proper divisors (14119363).

128421437 is a wasteful number, since it uses less digits than its factorization.

128421437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4736.

The product of its digits is 10752, while the sum is 32.

The square root of 128421437 is about 11332.3182535614. The cubic root of 128421437 is about 504.5209154450.

The spelling of 128421437 in words is "one hundred twenty-eight million, four hundred twenty-one thousand, four hundred thirty-seven".