39940478645761 has 4 divisors (see below), whose sum is σ = 40119583931392. Its totient is φ = 39761373360132.

The previous prime is 39940478645731. The next prime is 39940478645849. The reversal of 39940478645761 is 16754687404993.

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 39940478645761 - 2¹⁹ = 39940478121473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39940478645701) 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 3 ways as a sum of consecutive naturals, for example, 89552642481 + ... + 89552642926.

It is an arithmetic number, because the mean of its divisors is an integer number (10029895982848).

Almost surely, 2^{39940478645761} is an apocalyptic number.

It is an amenable number.

39940478645761 is a deficient number, since it is larger than the sum of its proper divisors (179105285631).

39940478645761 is a wasteful number, since it uses less digits than its factorization.

39940478645761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179105285630.

The product of its (nonzero) digits is 1097349120, while the sum is 73.

The spelling of 39940478645761 in words is "thirty-nine trillion, nine hundred forty billion, four hundred seventy-eight million, six hundred forty-five thousand, seven hundred sixty-one".