21110311321020 has 144 divisors (see below), whose sum is σ = 66720988134528. Its totient is φ = 5602736381760.

The previous prime is 21110311320979. The next prime is 21110311321027. The reversal of 21110311321020 is 2012311301112.

21110311321020 is a `hidden beast` number, since 2 + 1 + 1 + 10 + 311 + 321 + 0 + 20 = 666.

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 = 21110311320984 and 21110311321002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110311321027) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9267634 + ... + 11318553.

Almost surely, 2^{21110311321020} is an apocalyptic number.

21110311321020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110311321020 is an abundant number, since it is smaller than the sum of its proper divisors (45610676813508).

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

21110311321020 is a wasteful number, since it uses less digits than its factorization.

21110311321020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20586422 (or 20586408 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 21110311321020 its reverse (2012311301112), we get a palindrome (23122622622132).

The spelling of 21110311321020 in words is "twenty-one trillion, one hundred ten billion, three hundred eleven million, three hundred twenty-one thousand, twenty".