19640065557 has 16 divisors (see below), whose sum is σ = 29930964480. Its totient is φ = 11221677552.

The previous prime is 19640065547. The next prime is 19640065583. The reversal of 19640065557 is 75556004691.

It is not a de Polignac number, because 19640065557 - 2¹⁴ = 19640049173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19640065537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169858 + ... + 261020.

It is an arithmetic number, because the mean of its divisors is an integer number (1870685280).

Almost surely, 2^19640065557 is an apocalyptic number.

It is an amenable number.

19640065557 is a deficient number, since it is larger than the sum of its proper divisors (10290898923).

19640065557 is a wasteful number, since it uses less digits than its factorization.

19640065557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101432.

The product of its (nonzero) digits is 1134000, while the sum is 48.

The spelling of 19640065557 in words is "nineteen billion, six hundred forty million, sixty-five thousand, five hundred fifty-seven".