2155531 has 12 divisors (see below), whose sum is σ = 2602992. Its totient is φ = 1748304.

The previous prime is 2155519. The next prime is 2155579. The reversal of 2155531 is 1355512.

It is not a de Polignac number, because 2155531 - 2⁵ = 2155499 is a prime.

It is a super-2 number, since 2×2155531² = 9292627783922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2155511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2101 + ... + 2953.

It is an arithmetic number, because the mean of its divisors is an integer number (216916).

2^2155531 is an apocalyptic number.

2155531 is a deficient number, since it is larger than the sum of its proper divisors (447461).

2155531 is an equidigital number, since it uses as much as digits as its factorization.

2155531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 898 (or 879 counting only the distinct ones).

The product of its digits is 750, while the sum is 22.

The square root of 2155531 is about 1468.1726737683. The cubic root of 2155531 is about 129.1768701386.

The spelling of 2155531 in words is "two million, one hundred fifty-five thousand, five hundred thirty-one".