642003997 has 16 divisors (see below), whose sum is σ = 686070000. Its totient is φ = 598671360.

The previous prime is 642003961. The next prime is 642004039. The reversal of 642003997 is 799300246.

It can be written as a sum of positive squares in 8 ways, for example, as 125305636 + 516698361 = 11194^2 + 22731^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642003997 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 (642003917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1429629 + ... + 1430077.

It is an arithmetic number, because the mean of its divisors is an integer number (42879375).

Almost surely, 2^642003997 is an apocalyptic number.

It is an amenable number.

642003997 is a deficient number, since it is larger than the sum of its proper divisors (44066003).

642003997 is a wasteful number, since it uses less digits than its factorization.

642003997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056.

The product of its (nonzero) digits is 81648, while the sum is 40.

The square root of 642003997 is about 25337.7977930206. The cubic root of 642003997 is about 862.6724139533.

The spelling of 642003997 in words is "six hundred forty-two million, three thousand, nine hundred ninety-seven".