642987073 has 8 divisors (see below), whose sum is σ = 699210792. Its totient is φ = 588807936.

The previous prime is 642987071. The next prime is 642987077. The reversal of 642987073 is 370789246.

It can be written as a sum of positive squares in 4 ways, for example, as 489648384 + 153338689 = 22128^2 + 12383^2 .

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

It is not a de Polignac number, because 642987073 - 2¹ = 642987071 is a prime.

It is a super-3 number, since 3×642987073³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642987071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 510490 + ... + 511747.

It is an arithmetic number, because the mean of its divisors is an integer number (87401349).

Almost surely, 2^642987073 is an apocalyptic number.

It is an amenable number.

642987073 is a deficient number, since it is larger than the sum of its proper divisors (56223719).

642987073 is a wasteful number, since it uses less digits than its factorization.

642987073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1022291.

The product of its (nonzero) digits is 508032, while the sum is 46.

The square root of 642987073 is about 25357.1897693731. The cubic root of 642987073 is about 863.1125150764.

It can be divided in two parts, 642 and 987073, that added together give a triangular number (987715 = T₁₄₀₅).

The spelling of 642987073 in words is "six hundred forty-two million, nine hundred eighty-seven thousand, seventy-three".