505404445421 has 2 divisors, whose sum is σ = 505404445422. Its totient is φ = 505404445420.

The previous prime is 505404445409. The next prime is 505404445439. The reversal of 505404445421 is 124544404505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 366115755625 + 139288689796 = 605075^2 + 373214^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505404445421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505404445621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252702222710 + 252702222711.

It is an arithmetic number, because the mean of its divisors is an integer number (252702222711).

Almost surely, 2^505404445421 is an apocalyptic number.

It is an amenable number.

505404445421 is a deficient number, since it is larger than the sum of its proper divisors (1).

505404445421 is an equidigital number, since it uses as much as digits as its factorization.

505404445421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256000, while the sum is 38.

Adding to 505404445421 its reverse (124544404505), we get a palindrome (629948849926).

The spelling of 505404445421 in words is "five hundred five billion, four hundred four million, four hundred forty-five thousand, four hundred twenty-one".