185721496749 has 6 divisors (see below), whose sum is σ = 268264384206. Its totient is φ = 123814331160.

The previous prime is 185721496733. The next prime is 185721496769. The reversal of 185721496749 is 947694127581.

185721496749 is a `hidden beast` number, since 1 + 8 + 5 + 72 + 1 + 496 + 74 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 180327622500 + 5393874249 = 424650^2 + 73443^2 .

It is not a de Polignac number, because 185721496749 - 2⁴ = 185721496733 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (185721496769) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10317860922 + ... + 10317860939.

It is an arithmetic number, because the mean of its divisors is an integer number (44710730701).

Almost surely, 2^185721496749 is an apocalyptic number.

It is an amenable number.

185721496749 is a deficient number, since it is larger than the sum of its proper divisors (82542887457).

185721496749 is a wasteful number, since it uses less digits than its factorization.

185721496749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20635721867 (or 20635721864 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 63.

The spelling of 185721496749 in words is "one hundred eighty-five billion, seven hundred twenty-one million, four hundred ninety-six thousand, seven hundred forty-nine".