191418021 has 12 divisors (see below), whose sum is σ = 276622060. Its totient is φ = 127552320.

The previous prime is 191418001. The next prime is 191418047. The reversal of 191418021 is 120814191.

It can be written as a sum of positive squares in 2 ways, for example, as 88172100 + 103245921 = 9390^2 + 10161^2 .

It is not a de Polignac number, because 191418021 - 2⁹ = 191417509 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 (191418001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24561 + ... + 31401.

Almost surely, 2^191418021 is an apocalyptic number.

It is an amenable number.

191418021 is a deficient number, since it is larger than the sum of its proper divisors (85204039).

191418021 is a wasteful number, since it uses less digits than its factorization.

191418021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9956 (or 9953 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

The square root of 191418021 is about 13835.3901643575. The cubic root of 191418021 is about 576.3163500220.

The spelling of 191418021 in words is "one hundred ninety-one million, four hundred eighteen thousand, twenty-one".