42591649 has 2 divisors, whose sum is σ = 42591650. Its totient is φ = 42591648.

The previous prime is 42591643. The next prime is 42591667. The reversal of 42591649 is 94619524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41370624 + 1221025 = 6432^2 + 1105^2 .

It is a cyclic number.

It is not a de Polignac number, because 42591649 - 2⁵ = 42591617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42591643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21295824 + 21295825.

It is an arithmetic number, because the mean of its divisors is an integer number (21295825).

Almost surely, 2^42591649 is an apocalyptic number.

It is an amenable number.

42591649 is a deficient number, since it is larger than the sum of its proper divisors (1).

42591649 is an equidigital number, since it uses as much as digits as its factorization.

42591649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 40.

The square root of 42591649 is about 6526.2277772079. The cubic root of 42591649 is about 349.2272721023.

The spelling of 42591649 in words is "forty-two million, five hundred ninety-one thousand, six hundred forty-nine".