40001021 has 2 divisors, whose sum is σ = 40001022. Its totient is φ = 40001020.

The previous prime is 40000993. The next prime is 40001041. The reversal of 40001021 is 12010004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39564100 + 436921 = 6290^2 + 661^2 .

It is a cyclic number.

It is not a de Polignac number, because 40001021 - 2²² = 35806717 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40001041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20000510 + 20000511.

It is an arithmetic number, because the mean of its divisors is an integer number (20000511).

Almost surely, 2^40001021 is an apocalyptic number.

It is an amenable number.

40001021 is a deficient number, since it is larger than the sum of its proper divisors (1).

40001021 is an equidigital number, since it uses as much as digits as its factorization.

40001021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 40001021 is about 6324.6360369590. The cubic root of 40001021 is about 341.9980991197.

Adding to 40001021 its reverse (12010004), we get a palindrome (52011025).

The spelling of 40001021 in words is "forty million, one thousand, twenty-one".