191660378920 has 32 divisors (see below), whose sum is σ = 432515514600. Its totient is φ = 76436656128.

The previous prime is 191660378909. The next prime is 191660378981. The reversal of 191660378920 is 29873066191.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 175961792484 + 15698586436 = 419478^2 + 125294^2 .

It is a super-3 number, since 3×191660378920³ (a number of 35 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7095585 + ... + 7122544.

Almost surely, 2^191660378920 is an apocalyptic number.

191660378920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191660378920 is an abundant number, since it is smaller than the sum of its proper divisors (240855135680).

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

191660378920 is a wasteful number, since it uses less digits than its factorization.

191660378920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14218477 (or 14218473 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 52.

The spelling of 191660378920 in words is "one hundred ninety-one billion, six hundred sixty million, three hundred seventy-eight thousand, nine hundred twenty".