128423992651 has 4 divisors (see below), whose sum is σ = 128478022792. Its totient is φ = 128369962512.

The previous prime is 128423992649. The next prime is 128423992661. The reversal of 128423992651 is 156299324821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128423992651 - 2¹ = 128423992649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128423992621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27011505 + ... + 27016258.

It is an arithmetic number, because the mean of its divisors is an integer number (32119505698).

Almost surely, 2^128423992651 is an apocalyptic number.

128423992651 is a deficient number, since it is larger than the sum of its proper divisors (54030141).

128423992651 is an equidigital number, since it uses as much as digits as its factorization.

128423992651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54030140.

The product of its digits is 1866240, while the sum is 52.

The spelling of 128423992651 in words is "one hundred twenty-eight billion, four hundred twenty-three million, nine hundred ninety-two thousand, six hundred fifty-one".