19979565081 has 16 divisors (see below), whose sum is σ = 30449136000. Its totient is φ = 11415362688.

The previous prime is 19979565079. The next prime is 19979565091. The reversal of 19979565081 is 18056597991.

It is not a de Polignac number, because 19979565081 - 2¹ = 19979565079 is a prime.

It is a super-2 number, since 2×19979565081² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19979565041) 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, 107085 + ... + 226773.

It is an arithmetic number, because the mean of its divisors is an integer number (1903071000).

Almost surely, 2^19979565081 is an apocalyptic number.

It is an amenable number.

19979565081 is a deficient number, since it is larger than the sum of its proper divisors (10469570919).

19979565081 is a wasteful number, since it uses less digits than its factorization.

19979565081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127648.

The product of its (nonzero) digits is 6123600, while the sum is 60.

The spelling of 19979565081 in words is "nineteen billion, nine hundred seventy-nine million, five hundred sixty-five thousand, eighty-one".