19649620861389 has 10 divisors (see below), whose sum is σ = 29353137336270. Its totient is φ = 13099747240872.

The previous prime is 19649620861357. The next prime is 19649620861393. The reversal of 19649620861389 is 98316802694691.

19649620861389 is a `hidden beast` number, since 1 + 9 + 6 + 496 + 20 + 86 + 1 + 38 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17494494100164 + 2155126761225 = 4182642^2 + 1468035^2 .

It is not a de Polignac number, because 19649620861389 - 2⁵ = 19649620861357 is a prime.

It is a super-2 number, since 2×19649620861389² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19649620861309) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 121293955854 + ... + 121293956015.

It is an arithmetic number, because the mean of its divisors is an integer number (2935313733627).

Almost surely, 2^{19649620861389} is an apocalyptic number.

It is an amenable number.

19649620861389 is a deficient number, since it is larger than the sum of its proper divisors (9703516474881).

19649620861389 is an equidigital number, since it uses as much as digits as its factorization.

19649620861389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242587911881 (or 242587911872 counting only the distinct ones).

The product of its (nonzero) digits is 241864704, while the sum is 72.

The spelling of 19649620861389 in words is "nineteen trillion, six hundred forty-nine billion, six hundred twenty million, eight hundred sixty-one thousand, three hundred eighty-nine".