21030500421 has 16 divisors (see below), whose sum is σ = 35607196800. Its totient is φ = 12017428704.

The previous prime is 21030500389. The next prime is 21030500423. The reversal of 21030500421 is 12400503012.

21030500421 is a `hidden beast` number, since 210 + 30 + 5 + 0 + 0 + 421 = 666.

It is not a de Polignac number, because 21030500421 - 2⁵ = 21030500389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21030500394 and 21030500403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030500423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55636056 + ... + 55636433.

It is an arithmetic number, because the mean of its divisors is an integer number (2225449800).

Almost surely, 2^21030500421 is an apocalyptic number.

21030500421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21030500421 is a deficient number, since it is larger than the sum of its proper divisors (14576696379).

21030500421 is a wasteful number, since it uses less digits than its factorization.

21030500421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111272505 (or 111272499 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The spelling of 21030500421 in words is "twenty-one billion, thirty million, five hundred thousand, four hundred twenty-one".