19953820081 has 8 divisors (see below), whose sum is σ = 21490063784. Its totient is φ = 18417767040.

The previous prime is 19953820067. The next prime is 19953820109. The reversal of 19953820081 is 18002835991.

It can be written as a sum of positive squares in 4 ways, for example, as 13838400 + 19939981681 = 3720^2 + 141209^2 .

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 19953820081 - 2¹⁷ = 19953689009 is a prime.

It is a super-2 number, since 2×19953820081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19953860081) 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, 229375 + ... + 304171.

It is an arithmetic number, because the mean of its divisors is an integer number (2686257973).

Almost surely, 2^19953820081 is an apocalyptic number.

It is an amenable number.

19953820081 is a deficient number, since it is larger than the sum of its proper divisors (1536243703).

19953820081 is a wasteful number, since it uses less digits than its factorization.

19953820081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95331.

The product of its (nonzero) digits is 155520, while the sum is 46.

The spelling of 19953820081 in words is "nineteen billion, nine hundred fifty-three million, eight hundred twenty thousand, eighty-one".