21121203030 has 64 divisors (see below), whose sum is σ = 53184024576. Its totient is φ = 5361264000.

The previous prime is 21121203029. The next prime is 21121203031. The reversal of 21121203030 is 3030212112.

It is an interprime number because it is at equal distance from previous prime (21121203029) and next prime (21121203031).

It is a super-2 number, since 2×21121203030² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121203031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129426 + ... + 242885.

It is an arithmetic number, because the mean of its divisors is an integer number (831000384).

Almost surely, 2^21121203030 is an apocalyptic number.

21121203030 is an abundant number, since it is smaller than the sum of its proper divisors (32062821546).

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

21121203030 is a wasteful number, since it uses less digits than its factorization.

21121203030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372413.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21121203030 its reverse (3030212112), we get a palindrome (24151415142).

The spelling of 21121203030 in words is "twenty-one billion, one hundred twenty-one million, two hundred three thousand, thirty".