1021220151221 has 2 divisors, whose sum is σ = 1021220151222. Its totient is φ = 1021220151220.

The previous prime is 1021220151187. The next prime is 1021220151283. The reversal of 1021220151221 is 1221510221201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 994776838225 + 26443312996 = 997385^2 + 162614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021220151221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021220151193 and 1021220151202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021220151521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510610075610 + 510610075611.

It is an arithmetic number, because the mean of its divisors is an integer number (510610075611).

Almost surely, 2^{1021220151221} is an apocalyptic number.

It is an amenable number.

1021220151221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021220151221 is an equidigital number, since it uses as much as digits as its factorization.

1021220151221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 20.

Adding to 1021220151221 its reverse (1221510221201), we get a palindrome (2242730372422).

The spelling of 1021220151221 in words is "one trillion, twenty-one billion, two hundred twenty million, one hundred fifty-one thousand, two hundred twenty-one".