191931540400 has 30 divisors (see below), whose sum is σ = 461115526772. Its totient is φ = 76772616000.

The previous prime is 191931540389. The next prime is 191931540401. The reversal of 191931540400 is 4045139191.

It is a self number, because there is not a number n which added to its sum of digits gives 191931540400.

It is not an unprimeable number, because it can be changed into a prime (191931540401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 239914026 + ... + 239914825.

Almost surely, 2^191931540400 is an apocalyptic number.

191931540400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191931540400 is an abundant number, since it is smaller than the sum of its proper divisors (269183986372).

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

191931540400 is a wasteful number, since it uses less digits than its factorization.

191931540400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479828869 (or 479828858 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 37.

Adding to 191931540400 its reverse (4045139191), we get a palindrome (195976679591).

The spelling of 191931540400 in words is "one hundred ninety-one billion, nine hundred thirty-one million, five hundred forty thousand, four hundred".