4000400340661 has 4 divisors (see below), whose sum is σ = 4000431120192. Its totient is φ = 4000369561132.

The previous prime is 4000400340653. The next prime is 4000400340689. The reversal of 4000400340661 is 1660430040004.

It is a happy number.

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 4000400340661 - 2³ = 4000400340653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4000400340361) 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, 15193981 + ... + 15455026.

It is an arithmetic number, because the mean of its divisors is an integer number (1000107780048).

Almost surely, 2^{4000400340661} is an apocalyptic number.

It is an amenable number.

4000400340661 is a deficient number, since it is larger than the sum of its proper divisors (30779531).

4000400340661 is a wasteful number, since it uses less digits than its factorization.

4000400340661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30779530.

The product of its (nonzero) digits is 6912, while the sum is 28.

Adding to 4000400340661 its reverse (1660430040004), we get a palindrome (5660830380665).

The spelling of 4000400340661 in words is "four trillion, four hundred million, three hundred forty thousand, six hundred sixty-one".