21300128 has 12 divisors (see below), whose sum is σ = 41934690. Its totient is φ = 10650048.

The previous prime is 21300127. The next prime is 21300137. The reversal of 21300128 is 82100312.

It can be written as a sum of positive squares in only one way, i.e., 21270544 + 29584 = 4612^2 + 172^2 .

It is not an unprimeable number, because it can be changed into a prime (21300127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332783 + ... + 332846.

Almost surely, 2^21300128 is an apocalyptic number.

It is an amenable number.

21300128 is a deficient number, since it is larger than the sum of its proper divisors (20634562).

21300128 is an equidigital number, since it uses as much as digits as its factorization.

21300128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665639 (or 665631 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21300128 is about 4615.2061709094. The cubic root of 21300128 is about 277.2005394413.

The spelling of 21300128 in words is "twenty-one million, three hundred thousand, one hundred twenty-eight".