42086021 has 4 divisors (see below), whose sum is σ = 43915872. Its totient is φ = 40256172.

The previous prime is 42086017. The next prime is 42086041. The reversal of 42086021 is 12068024.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42086021 - 2² = 42086017 is a prime.

It is a super-2 number, since 2×42086021² = 3542466327224882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 1829827 = 42086021 / (4 + 2 + 0 + 8 + 6 + 0 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42086041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914891 + ... + 914936.

It is an arithmetic number, because the mean of its divisors is an integer number (10978968).

Almost surely, 2^42086021 is an apocalyptic number.

It is an amenable number.

42086021 is a deficient number, since it is larger than the sum of its proper divisors (1829851).

42086021 is a wasteful number, since it uses less digits than its factorization.

42086021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829850.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 42086021 is about 6487.3739679473. The cubic root of 42086021 is about 347.8398132054.

The spelling of 42086021 in words is "forty-two million, eighty-six thousand, twenty-one".