405981197 has 2 divisors, whose sum is σ = 405981198. Its totient is φ = 405981196.

The previous prime is 405981143. The next prime is 405981217. The reversal of 405981197 is 791189504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 360202441 + 45778756 = 18979^2 + 6766^2 .

It is a cyclic number.

It is not a de Polignac number, because 405981197 - 2⁶ = 405981133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405981127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202990598 + 202990599.

It is an arithmetic number, because the mean of its divisors is an integer number (202990599).

Almost surely, 2^405981197 is an apocalyptic number.

It is an amenable number.

405981197 is a deficient number, since it is larger than the sum of its proper divisors (1).

405981197 is an equidigital number, since it uses as much as digits as its factorization.

405981197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 44.

The square root of 405981197 is about 20148.9750855968. The cubic root of 405981197 is about 740.4606317623.

The spelling of 405981197 in words is "four hundred five million, nine hundred eighty-one thousand, one hundred ninety-seven".