1221885923257 has 2 divisors, whose sum is σ = 1221885923258. Its totient is φ = 1221885923256.

The previous prime is 1221885923221. The next prime is 1221885923369. The reversal of 1221885923257 is 7523295881221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1206436427641 + 15449495616 = 1098379^2 + 124296^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221885923257 is a prime.

It is a super-2 number, since 2×1221885923257² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221885923198 and 1221885923207.

It is not a weakly prime, because it can be changed into another prime (1221885923207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610942961628 + 610942961629.

It is an arithmetic number, because the mean of its divisors is an integer number (610942961629).

Almost surely, 2^{1221885923257} is an apocalyptic number.

It is an amenable number.

1221885923257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221885923257 is an equidigital number, since it uses as much as digits as its factorization.

1221885923257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4838400, while the sum is 55.

The spelling of 1221885923257 in words is "one trillion, two hundred twenty-one billion, eight hundred eighty-five million, nine hundred twenty-three thousand, two hundred fifty-seven".