2221531 has 4 divisors (see below), whose sum is σ = 2392432. Its totient is φ = 2050632.

The previous prime is 2221523. The next prime is 2221567. The reversal of 2221531 is 1351222.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1351222 = 2 ⋅675611.

It is a cyclic number.

It is not a de Polignac number, because 2221531 - 2³ = 2221523 is a prime.

It is a super-2 number, since 2×2221531² = 9870399967922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2221511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85431 + ... + 85456.

It is an arithmetic number, because the mean of its divisors is an integer number (598108).

2^2221531 is an apocalyptic number.

2221531 is a deficient number, since it is larger than the sum of its proper divisors (170901).

2221531 is a wasteful number, since it uses less digits than its factorization.

2221531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170900.

The product of its digits is 120, while the sum is 16.

The square root of 2221531 is about 1490.4801239869. The cubic root of 2221531 is about 130.4820564183.

Adding to 2221531 its reverse (1351222), we get a palindrome (3572753).

The spelling of 2221531 in words is "two million, two hundred twenty-one thousand, five hundred thirty-one".