642997241 has 2 divisors, whose sum is σ = 642997242. Its totient is φ = 642997240.

The previous prime is 642997237. The next prime is 642997283. The reversal of 642997241 is 142799246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 588547600 + 54449641 = 24260^2 + 7379^2 .

It is a cyclic number.

It is not a de Polignac number, because 642997241 - 2² = 642997237 is a prime.

It is a super-2 number, since 2×642997241² = 826890903867224162, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 642997192 and 642997201.

It is not a weakly prime, because it can be changed into another prime (642997291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321498620 + 321498621.

It is an arithmetic number, because the mean of its divisors is an integer number (321498621).

Almost surely, 2^642997241 is an apocalyptic number.

It is an amenable number.

642997241 is a deficient number, since it is larger than the sum of its proper divisors (1).

642997241 is an equidigital number, since it uses as much as digits as its factorization.

642997241 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 44.

The square root of 642997241 is about 25357.3902639842. The cubic root of 642997241 is about 863.1170647178.

The spelling of 642997241 in words is "six hundred forty-two million, nine hundred ninety-seven thousand, two hundred forty-one".