2215531 has 2 divisors, whose sum is σ = 2215532. Its totient is φ = 2215530.

The previous prime is 2215529. The next prime is 2215537. The reversal of 2215531 is 1355122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2215531 - 2¹ = 2215529 is a prime.

It is a super-2 number, since 2×2215531² = 9817155223922, which contains 22 as substring.

Together with 2215529, it forms a pair of twin primes.

It is a d-powerful number, because it can be written as 2¹² + 2¹⁶ + 1 + 5⁶ + 5⁹ + 3¹¹ + 1 .

2215531 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2215499 and 2215508.

It is not a weakly prime, because it can be changed into another prime (2215537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1107765 + 1107766.

It is an arithmetic number, because the mean of its divisors is an integer number (1107766).

2^2215531 is an apocalyptic number.

2215531 is a deficient number, since it is larger than the sum of its proper divisors (1).

2215531 is an equidigital number, since it uses as much as digits as its factorization.

2215531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 300, while the sum is 19.

The square root of 2215531 is about 1488.4659888624. The cubic root of 2215531 is about 130.3644801132.

The spelling of 2215531 in words is "two million, two hundred fifteen thousand, five hundred thirty-one".