21011210121012 has 24 divisors (see below), whose sum is σ = 49280178493056. Its totient is φ = 6967447915008.

The previous prime is 21011210120987. The next prime is 21011210121079. The reversal of 21011210121012 is 21012101211012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21011210120982 and 21011210121000.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4536096588 + ... + 4536101219.

It is an arithmetic number, because the mean of its divisors is an integer number (2053340770544).

Almost surely, 2^{21011210121012} is an apocalyptic number.

It is an amenable number.

21011210121012 is an abundant number, since it is smaller than the sum of its proper divisors (28268968372044).

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

21011210121012 is a wasteful number, since it uses less digits than its factorization.

21011210121012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9072198007 (or 9072198005 counting only the distinct ones).

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

Adding to 21011210121012 its reverse (21012101211012), we get a palindrome (42023311332024).

The spelling of 21011210121012 in words is "twenty-one trillion, eleven billion, two hundred ten million, one hundred twenty-one thousand, twelve".