400366646221 has 2 divisors, whose sum is σ = 400366646222. Its totient is φ = 400366646220.

The previous prime is 400366646153. The next prime is 400366646233. The reversal of 400366646221 is 122646663004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 240457833225 + 159908812996 = 490365^2 + 399886^2 .

It is a cyclic number.

It is not a de Polignac number, because 400366646221 - 2³³ = 391776711629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400366646261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200183323110 + 200183323111.

It is an arithmetic number, because the mean of its divisors is an integer number (200183323111).

Almost surely, 2^400366646221 is an apocalyptic number.

It is an amenable number.

400366646221 is a deficient number, since it is larger than the sum of its proper divisors (1).

400366646221 is an equidigital number, since it uses as much as digits as its factorization.

400366646221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 40.

The spelling of 400366646221 in words is "four hundred billion, three hundred sixty-six million, six hundred forty-six thousand, two hundred twenty-one".