400340209961 has 2 divisors, whose sum is σ = 400340209962. Its totient is φ = 400340209960.

The previous prime is 400340209949. The next prime is 400340210029. The reversal of 400340209961 is 169902043004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 263188494361 + 137151715600 = 513019^2 + 370340^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400340209961 is a prime.

It is not a weakly prime, because it can be changed into another prime (400340209261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200170104980 + 200170104981.

It is an arithmetic number, because the mean of its divisors is an integer number (200170104981).

Almost surely, 2^400340209961 is an apocalyptic number.

It is an amenable number.

400340209961 is a deficient number, since it is larger than the sum of its proper divisors (1).

400340209961 is an equidigital number, since it uses as much as digits as its factorization.

400340209961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 38.

The spelling of 400340209961 in words is "four hundred billion, three hundred forty million, two hundred nine thousand, nine hundred sixty-one".