40436021 has 2 divisors, whose sum is σ = 40436022. Its totient is φ = 40436020.

The previous prime is 40436017. The next prime is 40436029. The reversal of 40436021 is 12063404.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32376100 + 8059921 = 5690^2 + 2839^2 .

It is a cyclic number.

It is not a de Polignac number, because 40436021 - 2² = 40436017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 40435984 and 40436002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40436029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20218010 + 20218011.

It is an arithmetic number, because the mean of its divisors is an integer number (20218011).

Almost surely, 2^40436021 is an apocalyptic number.

It is an amenable number.

40436021 is a deficient number, since it is larger than the sum of its proper divisors (1).

40436021 is an equidigital number, since it uses as much as digits as its factorization.

40436021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 40436021 is about 6358.9323789454. The cubic root of 40436021 is about 343.2333437003.

Adding to 40436021 its reverse (12063404), we get a palindrome (52499425).

The spelling of 40436021 in words is "forty million, four hundred thirty-six thousand, twenty-one".