19965657601 has 8 divisors (see below), whose sum is σ = 20611467008. Its totient is φ = 19319958000.

The previous prime is 19965657581. The next prime is 19965657623. The reversal of 19965657601 is 10675656991.

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 19965657601 - 2⁷ = 19965657473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19965607601) 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, 508411 + ... + 546271.

It is an arithmetic number, because the mean of its divisors is an integer number (2576433376).

Almost surely, 2^19965657601 is an apocalyptic number.

It is an amenable number.

19965657601 is a deficient number, since it is larger than the sum of its proper divisors (645809407).

19965657601 is a wasteful number, since it uses less digits than its factorization.

19965657601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54903.

The product of its (nonzero) digits is 3061800, while the sum is 55.

The spelling of 19965657601 in words is "nineteen billion, nine hundred sixty-five million, six hundred fifty-seven thousand, six hundred one".