189821817690 has 32 divisors (see below), whose sum is σ = 464168071296. Its totient is φ = 49664072640.

The previous prime is 189821817673. The next prime is 189821817739. The reversal of 189821817690 is 96718128981.

It is a happy number.

It is a super-2 number, since 2×189821817690² (a number of 23 digits) contains 22 as substring.

It is a Curzon 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, 59690806 + ... + 59693985.

It is an arithmetic number, because the mean of its divisors is an integer number (14505252228).

Almost surely, 2^189821817690 is an apocalyptic number.

189821817690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

189821817690 is an abundant number, since it is smaller than the sum of its proper divisors (274346253606).

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

189821817690 is a wasteful number, since it uses less digits than its factorization.

189821817690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119384854.

The product of its (nonzero) digits is 3483648, while the sum is 60.

The spelling of 189821817690 in words is "one hundred eighty-nine billion, eight hundred twenty-one million, eight hundred seventeen thousand, six hundred ninety".