642542371 has 2 divisors, whose sum is σ = 642542372. Its totient is φ = 642542370.

The previous prime is 642542359. The next prime is 642542377. The reversal of 642542371 is 173245246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642542371 - 2⁵ = 642542339 is a prime.

It is not a weakly prime, because it can be changed into another prime (642542377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321271185 + 321271186.

It is an arithmetic number, because the mean of its divisors is an integer number (321271186).

Almost surely, 2^642542371 is an apocalyptic number.

642542371 is a deficient number, since it is larger than the sum of its proper divisors (1).

642542371 is an equidigital number, since it uses as much as digits as its factorization.

642542371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 34.

The square root of 642542371 is about 25348.4194970811. The cubic root of 642542371 is about 862.9134875483.

The spelling of 642542371 in words is "six hundred forty-two million, five hundred forty-two thousand, three hundred seventy-one".