21113031420 has 216 divisors, whose sum is σ = 73000090800. Its totient is φ = 4923389952.

The previous prime is 21113031419. The next prime is 21113031421. The reversal of 21113031420 is 2413031112.

21113031420 is a `hidden beast` number, since 211 + 1 + 3 + 0 + 31 + 420 = 666.

It is an interprime number because it is at equal distance from previous prime (21113031419) and next prime (21113031421).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21113031393 and 21113031402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113031421) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 559716 + ... + 596244.

Almost surely, 2^21113031420 is an apocalyptic number.

21113031420 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 21113031420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36500045400).

21113031420 is an abundant number, since it is smaller than the sum of its proper divisors (51887059380).

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

21113031420 is a wasteful number, since it uses less digits than its factorization.

21113031420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36589 (or 36571 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21113031420 its reverse (2413031112), we get a palindrome (23526062532).

The spelling of 21113031420 in words is "twenty-one billion, one hundred thirteen million, thirty-one thousand, four hundred twenty".