400011000021 has 16 divisors (see below), whose sum is σ = 593259429120. Its totient is φ = 266381256960.

The previous prime is 400011000019. The next prime is 400011000023. The reversal of 400011000021 is 120000110004.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (400011000019) and next prime (400011000023).

It is not a de Polignac number, because 400011000021 - 2¹ = 400011000019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 400010999967 and 400011000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400011000023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8106700 + ... + 8155893.

It is an arithmetic number, because the mean of its divisors is an integer number (37078714320).

Almost surely, 2^400011000021 is an apocalyptic number.

It is an amenable number.

400011000021 is a deficient number, since it is larger than the sum of its proper divisors (193248429099).

400011000021 is a wasteful number, since it uses less digits than its factorization.

400011000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16263513 (or 16263507 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 400011000021 its reverse (120000110004), we get a palindrome (520011110025).

The spelling of 400011000021 in words is "four hundred billion, eleven million, twenty-one", and thus it is an aban number.