42071621 has 4 divisors (see below), whose sum is σ = 42578592. Its totient is φ = 41564652.

The previous prime is 42071597. The next prime is 42071633. The reversal of 42071621 is 12617024.

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 a de Polignac number, because none of the positive numbers 2^k-42071621 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42071641) 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, 253361 + ... + 253526.

It is an arithmetic number, because the mean of its divisors is an integer number (10644648).

Almost surely, 2^42071621 is an apocalyptic number.

It is an amenable number.

42071621 is a deficient number, since it is larger than the sum of its proper divisors (506971).

42071621 is an equidigital number, since it uses as much as digits as its factorization.

42071621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506970.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 42071621 is about 6486.2640248451. The cubic root of 42071621 is about 347.8001368111.

Adding to 42071621 its reverse (12617024), we get a palindrome (54688645).

The spelling of 42071621 in words is "forty-two million, seventy-one thousand, six hundred twenty-one".