19949702647081 has 9 divisors (see below), whose sum is σ = 20007958765669. Its totient is φ = 19891615697536.

The previous prime is 19949702647067. The next prime is 19949702647097. The reversal of 19949702647081 is 18074620794991.

The square root of 19949702647081 is 4466509.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 10601151795481 + 9348550851600 = 3255941^2 + 3057540^2 .

It is not a de Polignac number, because 19949702647081 - 2¹⁹ = 19949702122793 is a prime.

It is a super-2 number, since 2×19949702647081² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19949702646998 and 19949702647016.

It is not an unprimeable number, because it can be changed into a prime (19949702647181) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1576671351 + ... + 1576684003.

Almost surely, 2^{19949702647081} is an apocalyptic number.

19949702647081 is the 4466509-th square number.

19949702647081 is the 2233255-th centered octagonal number.

It is an amenable number.

19949702647081 is a deficient number, since it is larger than the sum of its proper divisors (58256118588).

19949702647081 is an frugal number, since it uses more digits than its factorization.

19949702647081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26012 (or 13006 counting only the distinct ones).

The product of its (nonzero) digits is 54867456, while the sum is 67.

The spelling of 19949702647081 in words is "nineteen trillion, nine hundred forty-nine billion, seven hundred two million, six hundred forty-seven thousand, eighty-one".