21120430340 has 48 divisors (see below), whose sum is σ = 46439543808. Its totient is φ = 8053229184.

The previous prime is 21120430313. The next prime is 21120430351. The reversal of 21120430340 is 4303402112.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56429 + ... + 213131.

It is an arithmetic number, because the mean of its divisors is an integer number (967490496).

Almost surely, 2^21120430340 is an apocalyptic number.

21120430340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21120430340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23219771904).

21120430340 is an abundant number, since it is smaller than the sum of its proper divisors (25319113468).

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

21120430340 is a wasteful number, since it uses less digits than its factorization.

21120430340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157028 (or 157026 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21120430340 its reverse (4303402112), we get a palindrome (25423832452).

The spelling of 21120430340 in words is "twenty-one billion, one hundred twenty million, four hundred thirty thousand, three hundred forty".