642500623 has 2 divisors, whose sum is σ = 642500624. Its totient is φ = 642500622.

The previous prime is 642500569. The next prime is 642500629. The reversal of 642500623 is 326005246.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642500623 is a prime.

It is equal to p_33423805 and since 642500623 and 33423805 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 642500591 and 642500600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642500629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321250311 + 321250312.

It is an arithmetic number, because the mean of its divisors is an integer number (321250312).

Almost surely, 2^642500623 is an apocalyptic number.

642500623 is a deficient number, since it is larger than the sum of its proper divisors (1).

642500623 is an equidigital number, since it uses as much as digits as its factorization.

642500623 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 642500623 is about 25347.5960004100. The cubic root of 642500623 is about 862.8947984085.

Adding to 642500623 its reverse (326005246), we get a palindrome (968505869).

The spelling of 642500623 in words is "six hundred forty-two million, five hundred thousand, six hundred twenty-three".