401040021 has 16 divisors (see below), whose sum is σ = 544389120. Its totient is φ = 262555440.

The previous prime is 401039971. The next prime is 401040023. The reversal of 401040021 is 120040104.

It is not a de Polignac number, because 401040021 - 2¹⁸ = 400777877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 401039979 and 401040006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401040023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52440 + ... + 59598.

It is an arithmetic number, because the mean of its divisors is an integer number (34024320).

Almost surely, 2^401040021 is an apocalyptic number.

It is an amenable number.

401040021 is a deficient number, since it is larger than the sum of its proper divisors (143349099).

401040021 is a wasteful number, since it uses less digits than its factorization.

401040021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7496.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 401040021 is about 20025.9836462532. The cubic root of 401040021 is about 737.4443254343. Note that the first 3 decimals are identical.

Adding to 401040021 its reverse (120040104), we get a palindrome (521080125).

The spelling of 401040021 in words is "four hundred one million, forty thousand, twenty-one".