21001112121012 has 48 divisors (see below), whose sum is σ = 49120594482624. Its totient is φ = 6983514720000.

The previous prime is 21001112120951. The next prime is 21001112121023. The reversal of 21001112121012 is 21012121110012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21001112120982 and 21001112121000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235787887 + ... + 235876937.

It is an arithmetic number, because the mean of its divisors is an integer number (1023345718388).

Almost surely, 2^{21001112121012} is an apocalyptic number.

It is an amenable number.

21001112121012 is an abundant number, since it is smaller than the sum of its proper divisors (28119482361612).

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

21001112121012 is a wasteful number, since it uses less digits than its factorization.

21001112121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136160 (or 136158 counting only the distinct ones).

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

Adding to 21001112121012 its reverse (21012121110012), we get a palindrome (42013233231024).

The spelling of 21001112121012 in words is "twenty-one trillion, one billion, one hundred twelve million, one hundred twenty-one thousand, twelve".