642425401 has 2 divisors, whose sum is σ = 642425402. Its totient is φ = 642425400.

The previous prime is 642425341. The next prime is 642425449. The reversal of 642425401 is 104524246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 636250176 + 6175225 = 25224^2 + 2485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642425401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642425401.

It is not a weakly prime, because it can be changed into another prime (642425101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321212700 + 321212701.

It is an arithmetic number, because the mean of its divisors is an integer number (321212701).

Almost surely, 2^642425401 is an apocalyptic number.

It is an amenable number.

642425401 is a deficient number, since it is larger than the sum of its proper divisors (1).

642425401 is an equidigital number, since it uses as much as digits as its factorization.

642425401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 642425401 is about 25346.1121476253. The cubic root of 642425401 is about 862.8611220698.

Adding to 642425401 its reverse (104524246), we get a palindrome (746949647).

The spelling of 642425401 in words is "six hundred forty-two million, four hundred twenty-five thousand, four hundred one".