128363821 has 8 divisors (see below), whose sum is σ = 136608120. Its totient is φ = 120196608.

The previous prime is 128363813. The next prime is 128363843.

It is a happy number.

128363821 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 72488196 + 55875625 = 8514^2 + 7475^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128363821 - 2³ = 128363813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128360821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15816 + ... + 22513.

It is an arithmetic number, because the mean of its divisors is an integer number (17076015).

Almost surely, 2^128363821 is an apocalyptic number.

It is an amenable number.

128363821 is a deficient number, since it is larger than the sum of its proper divisors (8244299).

128363821 is a wasteful number, since it uses less digits than its factorization.

128363821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38543.

The product of its digits is 13824, while the sum is 34.

The square root of 128363821 is about 11329.7758583301. The cubic root of 128363821 is about 504.4454534194.

The spelling of 128363821 in words is "one hundred twenty-eight million, three hundred sixty-three thousand, eight hundred twenty-one".