21211011001020 has 96 divisors (see below), whose sum is σ = 60667792012800. Its totient is φ = 5535586172160.

The previous prime is 21211011000997. The next prime is 21211011001027. The reversal of 21211011001020 is 2010011011212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21211011000987 and 21211011001005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211011001027) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13832862 + ... + 15289541.

It is an arithmetic number, because the mean of its divisors is an integer number (631956166800).

Almost surely, 2^{21211011001020} is an apocalyptic number.

21211011001020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211011001020 is an abundant number, since it is smaller than the sum of its proper divisors (39456781011780).

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

21211011001020 is a wasteful number, since it uses less digits than its factorization.

21211011001020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29122675 (or 29122673 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21211011001020 its reverse (2010011011212), we get a palindrome (23221022012232).

The spelling of 21211011001020 in words is "twenty-one trillion, two hundred eleven billion, eleven million, one thousand, twenty".