191421797 has 4 divisors (see below), whose sum is σ = 218767776. Its totient is φ = 164075820.

The previous prime is 191421793. The next prime is 191421803. The reversal of 191421797 is 797124191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 191421797 - 2² = 191421793 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191421793) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13672979 + ... + 13672992.

It is an arithmetic number, because the mean of its divisors is an integer number (54691944).

Almost surely, 2^191421797 is an apocalyptic number.

It is an amenable number.

191421797 is a deficient number, since it is larger than the sum of its proper divisors (27345979).

191421797 is an equidigital number, since it uses as much as digits as its factorization.

191421797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27345978.

The product of its digits is 31752, while the sum is 41.

The square root of 191421797 is about 13835.5266253222. The cubic root of 191421797 is about 576.3201395576.

The spelling of 191421797 in words is "one hundred ninety-one million, four hundred twenty-one thousand, seven hundred ninety-seven".