40020997 has 2 divisors, whose sum is σ = 40020998. Its totient is φ = 40020996.

The previous prime is 40020991. The next prime is 40021001. The reversal of 40020997 is 79902004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39325441 + 695556 = 6271^2 + 834^2 .

It is a cyclic number.

It is not a de Polignac number, because 40020997 - 2²³ = 31632389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40020991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20010498 + 20010499.

It is an arithmetic number, because the mean of its divisors is an integer number (20010499).

Almost surely, 2^40020997 is an apocalyptic number.

It is an amenable number.

40020997 is a deficient number, since it is larger than the sum of its proper divisors (1).

40020997 is an equidigital number, since it uses as much as digits as its factorization.

40020997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 40020997 is about 6326.2150611562. The cubic root of 40020997 is about 342.0550194760.

The spelling of 40020997 in words is "forty million, twenty thousand, nine hundred ninety-seven".