21121011001211 has 4 divisors (see below), whose sum is σ = 23041102910424. Its totient is φ = 19200919092000.

The previous prime is 21121011001201. The next prime is 21121011001273. The reversal of 21121011001211 is 11210011012112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21121011001211 - 2¹⁸ = 21121010739067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121011001201) 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, 960045954590 + ... + 960045954611.

It is an arithmetic number, because the mean of its divisors is an integer number (5760275727606).

Almost surely, 2^{21121011001211} is an apocalyptic number.

21121011001211 is a deficient number, since it is larger than the sum of its proper divisors (1920091909213).

21121011001211 is a wasteful number, since it uses less digits than its factorization.

21121011001211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920091909212.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21121011001211 its reverse (11210011012112), we get a palindrome (32331022013323).

The spelling of 21121011001211 in words is "twenty-one trillion, one hundred twenty-one billion, eleven million, one thousand, two hundred eleven".