128639137445 has 128 divisors (see below), whose sum is σ = 210528460800. Its totient is φ = 73136701440.

The previous prime is 128639137409. The next prime is 128639137489. The reversal of 128639137445 is 544731936821.

It is not a de Polignac number, because 128639137445 - 2¹⁶ = 128639071909 is a prime.

It is a super-2 number, since 2×128639137445² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 17500631 + ... + 17507979.

It is an arithmetic number, because the mean of its divisors is an integer number (1644753600).

Almost surely, 2^128639137445 is an apocalyptic number.

It is an amenable number.

128639137445 is a deficient number, since it is larger than the sum of its proper divisors (81889323355).

128639137445 is a wasteful number, since it uses less digits than its factorization.

128639137445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7495.

The product of its digits is 4354560, while the sum is 53.

The spelling of 128639137445 in words is "one hundred twenty-eight billion, six hundred thirty-nine million, one hundred thirty-seven thousand, four hundred forty-five".