128226993 has 4 divisors (see below), whose sum is σ = 170969328. Its totient is φ = 85484660.

The previous prime is 128226983. The next prime is 128226997. The reversal of 128226993 is 399622821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128226993 - 2⁴ = 128226977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128226997) 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, 21371163 + ... + 21371168.

It is an arithmetic number, because the mean of its divisors is an integer number (42742332).

Almost surely, 2^128226993 is an apocalyptic number.

It is an amenable number.

128226993 is a deficient number, since it is larger than the sum of its proper divisors (42742335).

128226993 is an equidigital number, since it uses as much as digits as its factorization.

128226993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42742334.

The product of its digits is 93312, while the sum is 42.

The square root of 128226993 is about 11323.7358234816. The cubic root of 128226993 is about 504.2661536733.

The spelling of 128226993 in words is "one hundred twenty-eight million, two hundred twenty-six thousand, nine hundred ninety-three".