42091521 has 8 divisors (see below), whose sum is σ = 57932544. Its totient is φ = 27155760.

The previous prime is 42091519. The next prime is 42091523. The reversal of 42091521 is 12519024.

It is an interprime number because it is at equal distance from previous prime (42091519) and next prime (42091523).

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

It is not a de Polignac number, because 42091521 - 2¹ = 42091519 is a prime.

It is a super-2 number, since 2×42091521² = 3543392280186882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42091491 and 42091500.

It is not an unprimeable number, because it can be changed into a prime (42091523) 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, 226206 + ... + 226391.

It is an arithmetic number, because the mean of its divisors is an integer number (7241568).

Almost surely, 2^42091521 is an apocalyptic number.

It is an amenable number.

42091521 is a deficient number, since it is larger than the sum of its proper divisors (15841023).

42091521 is a wasteful number, since it uses less digits than its factorization.

42091521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452631.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 42091521 is about 6487.7978544341. The cubic root of 42091521 is about 347.8549649952.

The spelling of 42091521 in words is "forty-two million, ninety-one thousand, five hundred twenty-one".