42640927409 has 2 divisors, whose sum is σ = 42640927410. Its totient is φ = 42640927408.

The previous prime is 42640927387. The next prime is 42640927457. The reversal of 42640927409 is 90472904624.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23623690000 + 19017237409 = 153700^2 + 137903^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42640927409 is a prime.

It is not a weakly prime, because it can be changed into another prime (42640927009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21320463704 + 21320463705.

It is an arithmetic number, because the mean of its divisors is an integer number (21320463705).

Almost surely, 2^42640927409 is an apocalyptic number.

It is an amenable number.

42640927409 is a deficient number, since it is larger than the sum of its proper divisors (1).

42640927409 is an equidigital number, since it uses as much as digits as its factorization.

42640927409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 870912, while the sum is 47.

The spelling of 42640927409 in words is "forty-two billion, six hundred forty million, nine hundred twenty-seven thousand, four hundred nine".