185638385820 has 48 divisors (see below), whose sum is σ = 524933908128. Its totient is φ = 49013433600.

The previous prime is 185638385773. The next prime is 185638385861. The reversal of 185638385820 is 28583836581.

It is a happy number.

It is a super-2 number, since 2×185638385820² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15310639 + ... + 15322758.

It is an arithmetic number, because the mean of its divisors is an integer number (10936123086).

Almost surely, 2^185638385820 is an apocalyptic number.

185638385820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

185638385820 is an abundant number, since it is smaller than the sum of its proper divisors (339295522308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

185638385820 is a wasteful number, since it uses less digits than its factorization.

185638385820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30633510 (or 30633508 counting only the distinct ones).

The product of its (nonzero) digits is 11059200, while the sum is 57.

The spelling of 185638385820 in words is "one hundred eighty-five billion, six hundred thirty-eight million, three hundred eighty-five thousand, eight hundred twenty".