401212251221 has 2 divisors, whose sum is σ = 401212251222. Its totient is φ = 401212251220.

The previous prime is 401212251211. The next prime is 401212251239. The reversal of 401212251221 is 122152212104.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 375081528721 + 26130722500 = 612439^2 + 161650^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-401212251221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401212251211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200606125610 + 200606125611.

It is an arithmetic number, because the mean of its divisors is an integer number (200606125611).

Almost surely, 2^401212251221 is an apocalyptic number.

It is an amenable number.

401212251221 is a deficient number, since it is larger than the sum of its proper divisors (1).

401212251221 is an equidigital number, since it uses as much as digits as its factorization.

401212251221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 23.

Adding to 401212251221 its reverse (122152212104), we get a palindrome (523364463325).

The spelling of 401212251221 in words is "four hundred one billion, two hundred twelve million, two hundred fifty-one thousand, two hundred twenty-one".