40661993 has 2 divisors, whose sum is σ = 40661994. Its totient is φ = 40661992.

The previous prime is 40661989. The next prime is 40662019. The reversal of 40661993 is 39916604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34245904 + 6416089 = 5852^2 + 2533^2 .

It is a cyclic number.

It is not a de Polignac number, because 40661993 - 2² = 40661989 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (40661903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20330996 + 20330997.

It is an arithmetic number, because the mean of its divisors is an integer number (20330997).

Almost surely, 2^40661993 is an apocalyptic number.

It is an amenable number.

40661993 is a deficient number, since it is larger than the sum of its proper divisors (1).

40661993 is an equidigital number, since it uses as much as digits as its factorization.

40661993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 40661993 is about 6376.6757013353. The cubic root of 40661993 is about 343.8715295692.

The spelling of 40661993 in words is "forty million, six hundred sixty-one thousand, nine hundred ninety-three".