42870521 has 4 divisors (see below), whose sum is σ = 43597200. Its totient is φ = 42143844.

The previous prime is 42870493. The next prime is 42870547. The reversal of 42870521 is 12507824.

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 42870521 - 2¹⁴ = 42854137 is a prime.

It is a super-2 number, since 2×42870521² = 3675763141622882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42870571) 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, 363251 + ... + 363368.

It is an arithmetic number, because the mean of its divisors is an integer number (10899300).

Almost surely, 2^42870521 is an apocalyptic number.

It is an amenable number.

42870521 is a deficient number, since it is larger than the sum of its proper divisors (726679).

42870521 is an equidigital number, since it uses as much as digits as its factorization.

42870521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726678.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 42870521 is about 6547.5583998923. The cubic root of 42870521 is about 349.9878118205.

The spelling of 42870521 in words is "forty-two million, eight hundred seventy thousand, five hundred twenty-one".