405571961 has 2 divisors, whose sum is σ = 405571962. Its totient is φ = 405571960.

The previous prime is 405571927. The next prime is 405571963. The reversal of 405571961 is 169175504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 248220025 + 157351936 = 15755^2 + 12544^2 .

It is a cyclic number.

It is not a de Polignac number, because 405571961 - 2⁶ = 405571897 is a prime.

Together with 405571963, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (405571963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202785980 + 202785981.

It is an arithmetic number, because the mean of its divisors is an integer number (202785981).

Almost surely, 2^405571961 is an apocalyptic number.

It is an amenable number.

405571961 is a deficient number, since it is larger than the sum of its proper divisors (1).

405571961 is an equidigital number, since it uses as much as digits as its factorization.

405571961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 38.

The square root of 405571961 is about 20138.8172691447. The cubic root of 405571961 is about 740.2117491179.

The spelling of 405571961 in words is "four hundred five million, five hundred seventy-one thousand, nine hundred sixty-one".