40206613661 has 4 divisors (see below), whose sum is σ = 41141651232. Its totient is φ = 39271576092.

The previous prime is 40206613649. The next prime is 40206613669. The reversal of 40206613661 is 16631660204.

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 a de Polignac number, because none of the positive numbers 2^k-40206613661 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 (40206613669) 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, 467518721 + ... + 467518806.

It is an arithmetic number, because the mean of its divisors is an integer number (10285412808).

Almost surely, 2^40206613661 is an apocalyptic number.

It is an amenable number.

40206613661 is a deficient number, since it is larger than the sum of its proper divisors (935037571).

40206613661 is an equidigital number, since it uses as much as digits as its factorization.

40206613661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935037570.

The product of its (nonzero) digits is 31104, while the sum is 35.

The spelling of 40206613661 in words is "forty billion, two hundred six million, six hundred thirteen thousand, six hundred sixty-one".