1287258638 has 8 divisors (see below), whose sum is σ = 1983074232. Its totient is φ = 626233896.

The previous prime is 1287258619. The next prime is 1287258653. The reversal of 1287258638 is 8368527821.

It is a happy number.

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

It is a super-2 number, since 2×1287258638² = 3314069602211230088, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8697620 + ... + 8697767.

It is an arithmetic number, because the mean of its divisors is an integer number (247884279).

Almost surely, 2^1287258638 is an apocalyptic number.

1287258638 is a deficient number, since it is larger than the sum of its proper divisors (695815594).

1287258638 is a wasteful number, since it uses less digits than its factorization.

1287258638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17395426.

The product of its digits is 1290240, while the sum is 50.

The square root of 1287258638 is about 35878.3867809020. The cubic root of 1287258638 is about 1087.8155724510.

The spelling of 1287258638 in words is "one billion, two hundred eighty-seven million, two hundred fifty-eight thousand, six hundred thirty-eight".