1242989687 has 4 divisors (see below), whose sum is σ = 1260496656. Its totient is φ = 1225482720.

The previous prime is 1242989681. The next prime is 1242989771. The reversal of 1242989687 is 7869892421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7869892421 = 887 ⋅8872483.

It is not a de Polignac number, because 1242989687 - 2⁸ = 1242989431 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 (1242989681) 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, 8753378 + ... + 8753519.

It is an arithmetic number, because the mean of its divisors is an integer number (315124164).

Almost surely, 2^1242989687 is an apocalyptic number.

1242989687 is a deficient number, since it is larger than the sum of its proper divisors (17506969).

1242989687 is an equidigital number, since it uses as much as digits as its factorization.

1242989687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17506968.

The product of its digits is 3483648, while the sum is 56.

The square root of 1242989687 is about 35256.0588693631. The cubic root of 1242989687 is about 1075.1998004685.

The spelling of 1242989687 in words is "one billion, two hundred forty-two million, nine hundred eighty-nine thousand, six hundred eighty-seven".