21012101121210 has 16 divisors (see below), whose sum is σ = 50429042690976. Its totient is φ = 5603226965648.

The previous prime is 21012101121199. The next prime is 21012101121217. The reversal of 21012101121210 is 1212110121012.

It is a happy number.

It is a super-2 number, since 2×21012101121210² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21012101121210.

It is not an unprimeable number, because it can be changed into a prime (21012101121217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350201685324 + ... + 350201685383.

It is an arithmetic number, because the mean of its divisors is an integer number (3151815168186).

Almost surely, 2^{21012101121210} is an apocalyptic number.

21012101121210 is an abundant number, since it is smaller than the sum of its proper divisors (29416941569766).

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

21012101121210 is a wasteful number, since it uses less digits than its factorization.

21012101121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700403370717.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21012101121210 its reverse (1212110121012), we get a palindrome (22224211242222).

The spelling of 21012101121210 in words is "twenty-one trillion, twelve billion, one hundred one million, one hundred twenty-one thousand, two hundred ten".