39945469521 has 4 divisors (see below), whose sum is σ = 53260626032. Its totient is φ = 26630313012.

The previous prime is 39945469493. The next prime is 39945469567. The reversal of 39945469521 is 12596454993.

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 not a de Polignac number, because 39945469521 - 2⁷ = 39945469393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39945469621) 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, 6657578251 + ... + 6657578256.

It is an arithmetic number, because the mean of its divisors is an integer number (13315156508).

Almost surely, 2^39945469521 is an apocalyptic number.

It is an amenable number.

39945469521 is a deficient number, since it is larger than the sum of its proper divisors (13315156511).

39945469521 is a wasteful number, since it uses less digits than its factorization.

39945469521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13315156510.

The product of its digits is 10497600, while the sum is 57.

The spelling of 39945469521 in words is "thirty-nine billion, nine hundred forty-five million, four hundred sixty-nine thousand, five hundred twenty-one".