191320509604 has 81 divisors (see below), whose sum is σ = 393950019393. Its totient is φ = 81062837856.

The previous prime is 191320509517. The next prime is 191320509607. The reversal of 191320509604 is 406905023191.

The square root of 191320509604 is 437402.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 56078976100 + 135241533504 = 236810^2 + 367752^2 .

It is not an unprimeable number, because it can be changed into a prime (191320509607) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 961409497 + ... + 961409695.

Almost surely, 2^191320509604 is an apocalyptic number.

191320509604 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

191320509604 is the 437402-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191320509604

191320509604 is an abundant number, since it is smaller than the sum of its proper divisors (202629509789).

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

191320509604 is an equidigital number, since it uses as much as digits as its factorization.

191320509604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730 (or 365 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 40.

The spelling of 191320509604 in words is "one hundred ninety-one billion, three hundred twenty million, five hundred nine thousand, six hundred four".