21012020010121 has 16 divisors (see below), whose sum is σ = 24195061022976. Its totient is φ = 17874375630336.

The previous prime is 21012020010067. The next prime is 21012020010143. The reversal of 21012020010121 is 12101002021012.

It is a cyclic number.

It is not a de Polignac number, because 21012020010121 - 2¹¹ = 21012020008073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012020010721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1108705 + ... + 6576721.

It is an arithmetic number, because the mean of its divisors is an integer number (1512191313936).

Almost surely, 2^{21012020010121} is an apocalyptic number.

It is an amenable number.

21012020010121 is a deficient number, since it is larger than the sum of its proper divisors (3183041012855).

21012020010121 is a wasteful number, since it uses less digits than its factorization.

21012020010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5472168.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012020010121 its reverse (12101002021012), we get a palindrome (33113022031133).

The spelling of 21012020010121 in words is "twenty-one trillion, twelve billion, twenty million, ten thousand, one hundred twenty-one".