1221521223253 has 2 divisors, whose sum is σ = 1221521223254. Its totient is φ = 1221521223252.

The previous prime is 1221521223227. The next prime is 1221521223271. The reversal of 1221521223253 is 3523221251221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 647674067524 + 573847155729 = 804782^2 + 757527^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221521223253 is a prime.

It is a super-2 number, since 2×1221521223253² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221521223203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610760611626 + 610760611627.

It is an arithmetic number, because the mean of its divisors is an integer number (610760611627).

Almost surely, 2^{1221521223253} is an apocalyptic number.

It is an amenable number.

1221521223253 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221521223253 is an equidigital number, since it uses as much as digits as its factorization.

1221521223253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 31.

Adding to 1221521223253 its reverse (3523221251221), we get a palindrome (4744742474474).

The spelling of 1221521223253 in words is "one trillion, two hundred twenty-one billion, five hundred twenty-one million, two hundred twenty-three thousand, two hundred fifty-three".