191981351528 has 32 divisors (see below), whose sum is σ = 360901676520. Its totient is φ = 95741088000.

The previous prime is 191981351489. The next prime is 191981351533. The reversal of 191981351528 is 825153189191.

It can be written as a sum of positive squares in 4 ways, for example, as 122442606724 + 69538744804 = 349918^2 + 263702^2 .

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 191981351528.

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, 9656318 + ... + 9676178.

Almost surely, 2^191981351528 is an apocalyptic number.

It is an amenable number.

191981351528 is a deficient number, since it is larger than the sum of its proper divisors (168920324992).

191981351528 is a wasteful number, since it uses less digits than its factorization.

191981351528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22949 (or 22945 counting only the distinct ones).

The product of its digits is 777600, while the sum is 53.

The spelling of 191981351528 in words is "one hundred ninety-one billion, nine hundred eighty-one million, three hundred fifty-one thousand, five hundred twenty-eight".