1287540379 has 4 divisors (see below), whose sum is σ = 1287616176. Its totient is φ = 1287464584.

The previous prime is 1287540349. The next prime is 1287540389. The reversal of 1287540379 is 9730457821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1287540379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287540349) 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, 657 + ... + 50749.

It is an arithmetic number, because the mean of its divisors is an integer number (321904044).

Almost surely, 2^1287540379 is an apocalyptic number.

1287540379 is a deficient number, since it is larger than the sum of its proper divisors (75797).

1287540379 is an equidigital number, since it uses as much as digits as its factorization.

1287540379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75796.

The product of its (nonzero) digits is 423360, while the sum is 46.

The square root of 1287540379 is about 35882.3128992544. The cubic root of 1287540379 is about 1087.8949296941.

The spelling of 1287540379 in words is "one billion, two hundred eighty-seven million, five hundred forty thousand, three hundred seventy-nine".