642702987 has 24 divisors (see below), whose sum is σ = 1003630160. Its totient is φ = 394943040.

The previous prime is 642702979. The next prime is 642702997. The reversal of 642702987 is 789207246.

It is not a de Polignac number, because 642702987 - 2³ = 642702979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642702997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44464 + ... + 57117.

Almost surely, 2^642702987 is an apocalyptic number.

642702987 is a deficient number, since it is larger than the sum of its proper divisors (360927173).

642702987 is a wasteful number, since it uses less digits than its factorization.

642702987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101643 (or 101640 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 642702987 is about 25351.5874650879. The cubic root of 642702987 is about 862.9853822446.

The spelling of 642702987 in words is "six hundred forty-two million, seven hundred two thousand, nine hundred eighty-seven".