40709561 has 4 divisors (see below), whose sum is σ = 40725072. Its totient is φ = 40694052.

The previous prime is 40709551. The next prime is 40709573. The reversal of 40709561 is 16590704.

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 a de Polignac number, because none of the positive numbers 2^k-40709561 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a zygodrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (40709521) 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, 2735 + ... + 9428.

It is an arithmetic number, because the mean of its divisors is an integer number (10181268).

Almost surely, 2^40709561 is an apocalyptic number.

It is an amenable number.

40709561 is a deficient number, since it is larger than the sum of its proper divisors (15511).

40709561 is a wasteful number, since it uses less digits than its factorization.

40709561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15510.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 40709561 is about 6380.4044542646. The cubic root of 40709561 is about 344.0055687984.

It can be divided in two parts, 4070 and 9561, that added together give a palindrome (13631).

The spelling of 40709561 in words is "forty million, seven hundred nine thousand, five hundred sixty-one".