42691090 has 24 divisors (see below), whose sum is σ = 83213028. Its totient is φ = 15762240.

The previous prime is 42691079. The next prime is 42691091. The reversal of 42691090 is 9019624.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 558009 + 42133081 = 747^2 + 6491^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (42691091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10941 + ... + 14320.

Almost surely, 2^42691090 is an apocalyptic number.

42691090 is a deficient number, since it is larger than the sum of its proper divisors (40521938).

42691090 is a wasteful number, since it uses less digits than its factorization.

42691090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25294 (or 25281 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 42691090 is about 6533.8419019747. The cubic root of 42691090 is about 349.4988473857.

The spelling of 42691090 in words is "forty-two million, six hundred ninety-one thousand, ninety".