12021531 has 8 divisors (see below), whose sum is σ = 16110864. Its totient is φ = 7973280.

The previous prime is 12021491. The next prime is 12021539. The reversal of 12021531 is 13512021.

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

It is not a de Polignac number, because 12021531 - 2⁷ = 12021403 is a prime.

It is a super-2 number, since 2×12021531² = 289034415167922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12021531.

It is not an unprimeable number, because it can be changed into a prime (12021539) 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, 9580 + ... + 10761.

It is an arithmetic number, because the mean of its divisors is an integer number (2013858).

Almost surely, 2^12021531 is an apocalyptic number.

12021531 is a deficient number, since it is larger than the sum of its proper divisors (4089333).

12021531 is a wasteful number, since it uses less digits than its factorization.

12021531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20541.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 12021531 is about 3467.2079545363. The cubic root of 12021531 is about 229.0796936005.

Adding to 12021531 its reverse (13512021), we get a palindrome (25533552).

The spelling of 12021531 in words is "twelve million, twenty-one thousand, five hundred thirty-one".