11312121021 has 16 divisors (see below), whose sum is σ = 15149646336. Its totient is φ = 7508041776.

The previous prime is 11312121017. The next prime is 11312121047. The reversal of 11312121021 is 12012121311.

It is not a de Polignac number, because 11312121021 - 2² = 11312121017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11312123021) 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, 1640046 + ... + 1646928.

It is an arithmetic number, because the mean of its divisors is an integer number (946852896).

Almost surely, 2^11312121021 is an apocalyptic number.

It is an amenable number.

11312121021 is a deficient number, since it is larger than the sum of its proper divisors (3837525315).

11312121021 is a wasteful number, since it uses less digits than its factorization.

11312121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9232.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 11312121021 its reverse (12012121311), we get a palindrome (23324242332).

The spelling of 11312121021 in words is "eleven billion, three hundred twelve million, one hundred twenty-one thousand, twenty-one".