20010021012121 has 4 divisors (see below), whose sum is σ = 22868595442432. Its totient is φ = 17151446581812.

The previous prime is 20010021012073. The next prime is 20010021012127. The reversal of 20010021012121 is 12121012001002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20010021012121 - 2²¹ = 20010018914969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20010021012127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1429287215145 + ... + 1429287215158.

It is an arithmetic number, because the mean of its divisors is an integer number (5717148860608).

Almost surely, 2^{20010021012121} is an apocalyptic number.

It is an amenable number.

20010021012121 is a deficient number, since it is larger than the sum of its proper divisors (2858574430311).

20010021012121 is an equidigital number, since it uses as much as digits as its factorization.

20010021012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2858574430310.

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

Adding to 20010021012121 its reverse (12121012001002), we get a palindrome (32131033013123).

The spelling of 20010021012121 in words is "twenty trillion, ten billion, twenty-one million, twelve thousand, one hundred twenty-one".