42780523 has 2 divisors, whose sum is σ = 42780524. Its totient is φ = 42780522.

The previous prime is 42780503. The next prime is 42780541. The reversal of 42780523 is 32508724.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42780523 is a prime.

It is not a weakly prime, because it can be changed into another prime (42780503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21390261 + 21390262.

It is an arithmetic number, because the mean of its divisors is an integer number (21390262).

Almost surely, 2^42780523 is an apocalyptic number.

42780523 is a deficient number, since it is larger than the sum of its proper divisors (1).

42780523 is an equidigital number, since it uses as much as digits as its factorization.

42780523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 42780523 is about 6540.6821509687. The cubic root of 42780523 is about 349.7427306671.

The spelling of 42780523 in words is "forty-two million, seven hundred eighty thousand, five hundred twenty-three".