121231213021 has 16 divisors (see below), whose sum is σ = 131843299840. Its totient is φ = 111048744960.

The previous prime is 121231213001. The next prime is 121231213031. The reversal of 121231213021 is 120312132121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121231213021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121231213021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121231213001) 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, 589861 + ... + 768373.

It is an arithmetic number, because the mean of its divisors is an integer number (8240206240).

Almost surely, 2^121231213021 is an apocalyptic number.

It is an amenable number.

121231213021 is a deficient number, since it is larger than the sum of its proper divisors (10612086819).

121231213021 is a wasteful number, since it uses less digits than its factorization.

121231213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179716.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 121231213021 its reverse (120312132121), we get a palindrome (241543345142).

The spelling of 121231213021 in words is "one hundred twenty-one billion, two hundred thirty-one million, two hundred thirteen thousand, twenty-one".