196287391 has 4 divisors (see below), whose sum is σ = 196317112. Its totient is φ = 196257672.

The previous prime is 196287383. The next prime is 196287397. The reversal of 196287391 is 193782691.

It is a happy number.

196287391 is a nontrivial binomial coefficient, being equal to C(19814, 2).

It is a semiprime because it is the product of two primes.

It is a 3-Lehmer number, since φ(196287391) divides (196287391-1)³.

It is a cyclic number.

It is not a de Polignac number, because 196287391 - 2³ = 196287383 is a prime.

It is a deceptive number, since it divides R_196287390.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (196287397) 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, 1 + ... + 19813.

It is an arithmetic number, because the mean of its divisors is an integer number (49079278).

Almost surely, 2^196287391 is an apocalyptic number.

196287391 is the 19813-rd triangular number and also the 9907-th hexagonal number.

196287391 is the 6605-th centered nonagonal number.

196287391 is a deficient number, since it is larger than the sum of its proper divisors (29721).

196287391 is an equidigital number, since it uses as much as digits as its factorization.

196287391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29720.

The product of its digits is 163296, while the sum is 46.

The square root of 196287391 is about 14010.2602045786. The cubic root of 196287391 is about 581.1623450353.

The spelling of 196287391 in words is "one hundred ninety-six million, two hundred eighty-seven thousand, three hundred ninety-one".