40010021 has 4 divisors (see below), whose sum is σ = 40101600. Its totient is φ = 39918444.

The previous prime is 40010011. The next prime is 40010051. The reversal of 40010021 is 12001004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40010021 - 2¹⁴ = 39993637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40009990 and 40010008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40010011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45131 + ... + 46008.

It is an arithmetic number, because the mean of its divisors is an integer number (10025400).

Almost surely, 2^40010021 is an apocalyptic number.

It is an amenable number.

40010021 is a deficient number, since it is larger than the sum of its proper divisors (91579).

40010021 is an equidigital number, since it uses as much as digits as its factorization.

40010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91578.

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

The square root of 40010021 is about 6325.3475003355. The cubic root of 40010021 is about 342.0237463990.

Adding to 40010021 its reverse (12001004), we get a palindrome (52011025).

The spelling of 40010021 in words is "forty million, ten thousand, twenty-one".