21111021201270 has 256 divisors, whose sum is σ = 68050003875840. Its totient is φ = 4047938150400.

The previous prime is 21111021201181. The next prime is 21111021201271. The reversal of 21111021201270 is 7210212011112.

It is a super-2 number, since 2×21111021201270² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111021201271) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 92648880 + ... + 92876460.

It is an arithmetic number, because the mean of its divisors is an integer number (265820327640).

Almost surely, 2^{21111021201270} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111021201270, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34025001937920).

21111021201270 is an abundant number, since it is smaller than the sum of its proper divisors (46938982674570).

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

21111021201270 is a wasteful number, since it uses less digits than its factorization.

21111021201270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230711.

The product of its (nonzero) digits is 112, while the sum is 21.

Adding to 21111021201270 its reverse (7210212011112), we get a palindrome (28321233212382).

The spelling of 21111021201270 in words is "twenty-one trillion, one hundred eleven billion, twenty-one million, two hundred one thousand, two hundred seventy".