19891609245 has 24 divisors (see below), whose sum is σ = 34601511672. Its totient is φ = 10571097600.

The previous prime is 19891609207. The next prime is 19891609249. The reversal of 19891609245 is 54290619891.

19891609245 is a `hidden beast` number, since 1 + 9 + 8 + 9 + 1 + 609 + 24 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5794558884 + 14097050361 = 76122^2 + 118731^2 .

It is not a de Polignac number, because 19891609245 - 2⁷ = 19891609117 is a prime.

It is a super-2 number, since 2×19891609245² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19891609191 and 19891609200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891609249) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 773896 + ... + 799185.

It is an arithmetic number, because the mean of its divisors is an integer number (1441729653).

Almost surely, 2^19891609245 is an apocalyptic number.

19891609245 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19891609245 is a deficient number, since it is larger than the sum of its proper divisors (14709902427).

19891609245 is a wasteful number, since it uses less digits than its factorization.

19891609245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1573373 (or 1573370 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 19891609245 in words is "nineteen billion, eight hundred ninety-one million, six hundred nine thousand, two hundred forty-five".