1221232012021 has 16 divisors (see below), whose sum is σ = 1416759282304. Its totient is φ = 1030976299584.

The previous prime is 1221232012019. The next prime is 1221232012031. The reversal of 1221232012021 is 1202102321221.

It is not a de Polignac number, because 1221232012021 - 2¹ = 1221232012019 is a prime.

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 1221232012021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221232012031) 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, 2664091 + ... + 3088663.

It is an arithmetic number, because the mean of its divisors is an integer number (88547455144).

Almost surely, 2^{1221232012021} is an apocalyptic number.

It is an amenable number.

1221232012021 is a deficient number, since it is larger than the sum of its proper divisors (195527270283).

1221232012021 is an equidigital number, since it uses as much as digits as its factorization.

1221232012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430780.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 1221232012021 its reverse (1202102321221), we get a palindrome (2423334333242).

The spelling of 1221232012021 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-two million, twelve thousand, twenty-one".