42186649 has 2 divisors, whose sum is σ = 42186650. Its totient is φ = 42186648.

The previous prime is 42186647. The next prime is 42186653. The reversal of 42186649 is 94668124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41990400 + 196249 = 6480^2 + 443^2 .

It is a cyclic number.

It is not a de Polignac number, because 42186649 - 2¹ = 42186647 is a prime.

Together with 42186647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42186643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21093324 + 21093325.

It is an arithmetic number, because the mean of its divisors is an integer number (21093325).

Almost surely, 2^42186649 is an apocalyptic number.

It is an amenable number.

42186649 is a deficient number, since it is larger than the sum of its proper divisors (1).

42186649 is an equidigital number, since it uses as much as digits as its factorization.

42186649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 40.

The square root of 42186649 is about 6495.1250180424. The cubic root of 42186649 is about 348.1168217692.

The spelling of 42186649 in words is "forty-two million, one hundred eighty-six thousand, six hundred forty-nine".