21111120120020 has 48 divisors (see below), whose sum is σ = 50668569694848. Its totient is φ = 7237829554560.

The previous prime is 21111120120011. The next prime is 21111120120029. The reversal of 21111120120020 is 2002102111112.

It is an interprime number because it is at equal distance from previous prime (21111120120011) and next prime (21111120120029).

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21111120119977 and 21111120120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111120120029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1002359 + ... + 6574721.

It is an arithmetic number, because the mean of its divisors is an integer number (1055595201976).

Almost surely, 2^{21111120120020} is an apocalyptic number.

21111120120020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111120120020 is an abundant number, since it is smaller than the sum of its proper divisors (29557449574828).

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

21111120120020 is a wasteful number, since it uses less digits than its factorization.

21111120120020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5599440 (or 5599438 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21111120120020 its reverse (2002102111112), we get a palindrome (23113222231132).

The spelling of 21111120120020 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty million, one hundred twenty thousand, twenty".