21114421020 has 144 divisors (see below), whose sum is σ = 79850953728. Its totient is φ = 4387409280.

The previous prime is 21114420991. The next prime is 21114421049. The reversal of 21114421020 is 2012441112.

21114421020 is a `hidden beast` number, since 211 + 1 + 442 + 10 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21114420991) and next prime (21114421049).

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 = 21114420984 and 21114421002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 747844 + ... + 775563.

It is an arithmetic number, because the mean of its divisors is an integer number (554520512).

Almost surely, 2^21114421020 is an apocalyptic number.

21114421020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21114421020 is an abundant number, since it is smaller than the sum of its proper divisors (58736532708).

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

21114421020 is a wasteful number, since it uses less digits than its factorization.

21114421020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523440 (or 1523435 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21114421020 its reverse (2012441112), we get a palindrome (23126862132).

The spelling of 21114421020 in words is "twenty-one billion, one hundred fourteen million, four hundred twenty-one thousand, twenty".