10211212121 has 4 divisors (see below), whose sum is σ = 11139504144. Its totient is φ = 9282920100.

The previous prime is 10211212111. The next prime is 10211212133. The reversal of 10211212121 is 12121211201.

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 10211212121 - 2¹⁴ = 10211195737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10211212096 and 10211212105.

It is not an unprimeable number, because it can be changed into a prime (10211212111) 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, 464145995 + ... + 464146016.

It is an arithmetic number, because the mean of its divisors is an integer number (2784876036).

Almost surely, 2^10211212121 is an apocalyptic number.

10211212121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

10211212121 is a deficient number, since it is larger than the sum of its proper divisors (928292023).

10211212121 is an equidigital number, since it uses as much as digits as its factorization.

10211212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928292022.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 10211212121 its reverse (12121211201), we get a palindrome (22332423322).

The spelling of 10211212121 in words is "ten billion, two hundred eleven million, two hundred twelve thousand, one hundred twenty-one".