2181497 has 4 divisors (see below), whose sum is σ = 2196096. Its totient is φ = 2166900.

The previous prime is 2181469. The next prime is 2181503. The reversal of 2181497 is 7941812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2181497 - 2¹² = 2177401 is a prime.

It is a super-2 number, since 2×2181497² = 9517858322018, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7073 + ... + 7374.

It is an arithmetic number, because the mean of its divisors is an integer number (549024).

2^2181497 is an apocalyptic number.

It is an amenable number.

2181497 is a deficient number, since it is larger than the sum of its proper divisors (14599).

2181497 is a wasteful number, since it uses less digits than its factorization.

2181497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14598.

The product of its digits is 4032, while the sum is 32.

The square root of 2181497 is about 1476.9891671911. The cubic root of 2181497 is about 129.6934988370.

Adding to 2181497 its sum of digits (32), we get a square (2181529 = 1477²).

It can be divided in two parts, 21 and 81497, that added together give a palindrome (81518).

The spelling of 2181497 in words is "two million, one hundred eighty-one thousand, four hundred ninety-seven".