191720871936 has 864 divisors, whose sum is σ = 652516300800. Its totient is φ = 54094233600.

The previous prime is 191720871931. The next prime is 191720871959. The reversal of 191720871936 is 639178027191.

It is a happy number.

It is a super-2 number, since 2×191720871936² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191720871931) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3249506275 + ... + 3249506333.

It is an arithmetic number, because the mean of its divisors is an integer number (755227200).

Almost surely, 2^191720871936 is an apocalyptic number.

191720871936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191720871936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326258150400).

191720871936 is an abundant number, since it is smaller than the sum of its proper divisors (460795428864).

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

191720871936 is a wasteful number, since it uses less digits than its factorization.

191720871936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 54.

The spelling of 191720871936 in words is "one hundred ninety-one billion, seven hundred twenty million, eight hundred seventy-one thousand, nine hundred thirty-six".