21203232128 has 48 divisors (see below), whose sum is σ = 45740099700. Its totient is φ = 9786097152.

The previous prime is 21203232121. The next prime is 21203232131. The reversal of 21203232128 is 82123230212.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 21203232097 and 21203232106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203232121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 468458 + ... + 511721.

Almost surely, 2^21203232128 is an apocalyptic number.

It is an amenable number.

21203232128 is an abundant number, since it is smaller than the sum of its proper divisors (24536867572).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21203232128 is an equidigital number, since it uses as much as digits as its factorization.

21203232128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980219 (or 980194 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The spelling of 21203232128 in words is "twenty-one billion, two hundred three million, two hundred thirty-two thousand, one hundred twenty-eight".