128973638641 has 3 divisors (see below), whose sum is σ = 128973997771. Its totient is φ = 128973279512.

The previous prime is 128973638639. The next prime is 128973638653. The reversal of 128973638641 is 146836379821.

The square root of 128973638641 is 359129.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 146836379821 = 23 ⋅6384190427.

It can be written as a sum of positive squares in only one way, i.e., 12392365041 + 116581273600 = 111321^2 + 341440^2 .

It is not a de Polignac number, because 128973638641 - 2¹ = 128973638639 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128973630641) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 179565 + ... + 538693.

Almost surely, 2^128973638641 is an apocalyptic number.

128973638641 is the 359129-th square number.

128973638641 is the 179565-th centered octagonal number.

It is an amenable number.

128973638641 is a deficient number, since it is larger than the sum of its proper divisors (359130).

128973638641 is an frugal number, since it uses more digits than its factorization.

128973638641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718258 (or 359129 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 58.

The spelling of 128973638641 in words is "one hundred twenty-eight billion, nine hundred seventy-three million, six hundred thirty-eight thousand, six hundred forty-one".