19755640757 has 4 divisors (see below), whose sum is σ = 19888229100. Its totient is φ = 19623052416.

The previous prime is 19755640747. The next prime is 19755640819. The reversal of 19755640757 is 75704655791.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75704655791 = 61 ⋅1241059931.

It can be written as a sum of positive squares in 2 ways, for example, as 3216137521 + 16539503236 = 56711^2 + 128606^2 .

It is a cyclic number.

It is not a de Polignac number, because 19755640757 - 2¹² = 19755636661 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 (19755640717) 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, 66293948 + ... + 66294245.

It is an arithmetic number, because the mean of its divisors is an integer number (4972057275).

Almost surely, 2^19755640757 is an apocalyptic number.

It is an amenable number.

19755640757 is a deficient number, since it is larger than the sum of its proper divisors (132588343).

19755640757 is a wasteful number, since it uses less digits than its factorization.

19755640757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132588342.

The product of its (nonzero) digits is 9261000, while the sum is 56.

The spelling of 19755640757 in words is "nineteen billion, seven hundred fifty-five million, six hundred forty thousand, seven hundred fifty-seven".