42100521 has 4 divisors (see below), whose sum is σ = 56134032. Its totient is φ = 28067012.

The previous prime is 42100519. The next prime is 42100543. The reversal of 42100521 is 12500124.

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 42100521 - 2¹ = 42100519 is a prime.

It is a super-3 number, since 3×42100521³ (a number of 24 digits) contains 333 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42100521.

It is not an unprimeable number, because it can be changed into a prime (42100501) 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 3 ways as a sum of consecutive naturals, for example, 7016751 + ... + 7016756.

It is an arithmetic number, because the mean of its divisors is an integer number (14033508).

Almost surely, 2^42100521 is an apocalyptic number.

It is an amenable number.

42100521 is a deficient number, since it is larger than the sum of its proper divisors (14033511).

42100521 is a wasteful number, since it uses less digits than its factorization.

42100521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14033510.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 42100521 is about 6488.4914271347. The cubic root of 42100521 is about 347.8797559864.

Adding to 42100521 its reverse (12500124), we get a palindrome (54600645).

The spelling of 42100521 in words is "forty-two million, one hundred thousand, five hundred twenty-one".