42187081 has 8 divisors (see below), whose sum is σ = 45066024. Its totient is φ = 39352320.

The previous prime is 42187069. The next prime is 42187111. The reversal of 42187081 is 18078124.

It can be written as a sum of positive squares in 4 ways, for example, as 5475600 + 36711481 = 2340^2 + 6059^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42187081 - 2⁷ = 42186953 is a prime.

It is a super-2 number, since 2×42187081² = 3559499606601122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42187021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9060 + ... + 12901.

It is an arithmetic number, because the mean of its divisors is an integer number (5633253).

Almost surely, 2^42187081 is an apocalyptic number.

It is an amenable number.

42187081 is a deficient number, since it is larger than the sum of its proper divisors (2878943).

42187081 is a wasteful number, since it uses less digits than its factorization.

42187081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22091.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 42187081 is about 6495.1582736682. The cubic root of 42187081 is about 348.1180100278.

The spelling of 42187081 in words is "forty-two million, one hundred eighty-seven thousand, eighty-one".