40100021 has 4 divisors (see below), whose sum is σ = 43184652. Its totient is φ = 37015392.

The previous prime is 40100003. The next prime is 40100041. The reversal of 40100021 is 12000104.

40100021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12327121 + 27772900 = 3511^2 + 5270^2 .

It is a cyclic number.

It is not a de Polignac number, because 40100021 - 2¹⁰ = 40098997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40099981 and 40100008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40100041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1542296 + ... + 1542321.

It is an arithmetic number, because the mean of its divisors is an integer number (10796163).

Almost surely, 2^40100021 is an apocalyptic number.

It is an amenable number.

40100021 is a deficient number, since it is larger than the sum of its proper divisors (3084631).

40100021 is a wasteful number, since it uses less digits than its factorization.

40100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3084630.

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

The square root of 40100021 is about 6332.4577377192. The cubic root of 40100021 is about 342.2800079087.

Adding to 40100021 its reverse (12000104), we get a palindrome (52100125).

The spelling of 40100021 in words is "forty million, one hundred thousand, twenty-one".