4000400001 has 32 divisors (see below), whose sum is σ = 6386186240. Its totient is φ = 2460326400.

The previous prime is 4000399981. The next prime is 4000400023. The reversal of 4000400001 is 1000040004.

It is not a de Polignac number, because 4000400001 - 2⁵ = 4000399969 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4000400071) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1178016 + ... + 1181406.

It is an arithmetic number, because the mean of its divisors is an integer number (199568320).

Almost surely, 2^4000400001 is an apocalyptic number.

It is an amenable number.

4000400001 is a deficient number, since it is larger than the sum of its proper divisors (2385786239).

4000400001 is a wasteful number, since it uses less digits than its factorization.

4000400001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6774 (or 6768 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 4000400001 is about 63248.7154098801. The cubic root of 4000400001 is about 1587.4539637052.

Adding to 4000400001 its reverse (1000040004), we get a palindrome (5000440005).

It can be divided in two parts, 400040000 and 1, that added together give a square (400040001 = 20001²).

The spelling of 4000400001 in words is "four billion, four hundred thousand, one".