642294691 has 2 divisors, whose sum is σ = 642294692. Its totient is φ = 642294690.

The previous prime is 642294641. The next prime is 642294701. The reversal of 642294691 is 196492246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642294691 - 2¹¹ = 642292643 is a prime.

It is not a weakly prime, because it can be changed into another prime (642294641) 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, 321147345 + 321147346.

It is an arithmetic number, because the mean of its divisors is an integer number (321147346).

Almost surely, 2^642294691 is an apocalyptic number.

642294691 is a deficient number, since it is larger than the sum of its proper divisors (1).

642294691 is an equidigital number, since it uses as much as digits as its factorization.

642294691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 43.

The square root of 642294691 is about 25343.5335144885. The cubic root of 642294691 is about 862.8025979065.

The spelling of 642294691 in words is "six hundred forty-two million, two hundred ninety-four thousand, six hundred ninety-one".