287640393 has 8 divisors (see below), whose sum is σ = 383600256. Its totient is φ = 191720400.

The previous prime is 287640389. The next prime is 287640421. The reversal of 287640393 is 393046782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 287640393 - 2² = 287640389 is a prime.

It is not an unprimeable number, because it can be changed into a prime (287644393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18423 + ... + 30243.

It is an arithmetic number, because the mean of its divisors is an integer number (47950032).

Almost surely, 2^287640393 is an apocalyptic number.

It is an amenable number.

287640393 is a deficient number, since it is larger than the sum of its proper divisors (95959863).

287640393 is a wasteful number, since it uses less digits than its factorization.

287640393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19935.

The product of its (nonzero) digits is 217728, while the sum is 42.

The square root of 287640393 is about 16959.9644162363. The cubic root of 287640393 is about 660.1104750790.

The spelling of 287640393 in words is "two hundred eighty-seven million, six hundred forty thousand, three hundred ninety-three".