642414251 has 2 divisors, whose sum is σ = 642414252. Its totient is φ = 642414250.

The previous prime is 642414229. The next prime is 642414287. The reversal of 642414251 is 152414246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642414251 - 2¹⁸ = 642152107 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (642414211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321207125 + 321207126.

It is an arithmetic number, because the mean of its divisors is an integer number (321207126).

Almost surely, 2^642414251 is an apocalyptic number.

642414251 is a deficient number, since it is larger than the sum of its proper divisors (1).

642414251 is an equidigital number, since it uses as much as digits as its factorization.

642414251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7680, while the sum is 29.

The square root of 642414251 is about 25345.8921918326. The cubic root of 642414251 is about 862.8561300727.

Adding to 642414251 its reverse (152414246), we get a palindrome (794828497).

The spelling of 642414251 in words is "six hundred forty-two million, four hundred fourteen thousand, two hundred fifty-one".