9940075578721 has 8 divisors (see below), whose sum is σ = 9942770407464. Its totient is φ = 9937381002240.

The previous prime is 9940075578701. The next prime is 9940075578757. The reversal of 9940075578721 is 1278755700499.

It can be written as a sum of positive squares in 4 ways, for example, as 4442757606225 + 5497317972496 = 2107785^2 + 2344636^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9940075578721 - 2⁴³ = 1143982556513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9940075578701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99115615 + ... + 99215851.

It is an arithmetic number, because the mean of its divisors is an integer number (1242846300933).

Almost surely, 2^{9940075578721} is an apocalyptic number.

It is an amenable number.

9940075578721 is a deficient number, since it is larger than the sum of its proper divisors (2694828743).

9940075578721 is a wasteful number, since it uses less digits than its factorization.

9940075578721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126131.

The product of its (nonzero) digits is 44452800, while the sum is 64.

The spelling of 9940075578721 in words is "nine trillion, nine hundred forty billion, seventy-five million, five hundred seventy-eight thousand, seven hundred twenty-one".