400371427721 has 2 divisors, whose sum is σ = 400371427722. Its totient is φ = 400371427720.

The previous prime is 400371427699. The next prime is 400371427723. The reversal of 400371427721 is 127724173004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 215471427721 + 184900000000 = 464189^2 + 430000^2 .

It is a cyclic number.

It is not a de Polignac number, because 400371427721 - 2²² = 400367233417 is a prime.

It is a Sophie Germain prime.

Together with 400371427723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (400371427723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200185713860 + 200185713861.

It is an arithmetic number, because the mean of its divisors is an integer number (200185713861).

Almost surely, 2^400371427721 is an apocalyptic number.

It is an amenable number.

400371427721 is a deficient number, since it is larger than the sum of its proper divisors (1).

400371427721 is an equidigital number, since it uses as much as digits as its factorization.

400371427721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 65856, while the sum is 38.

The spelling of 400371427721 in words is "four hundred billion, three hundred seventy-one million, four hundred twenty-seven thousand, seven hundred twenty-one".