2731621 has 2 divisors, whose sum is σ = 2731622. Its totient is φ = 2731620.

The previous prime is 2731609. The next prime is 2731637. The reversal of 2731621 is 1261372.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2515396 + 216225 = 1586^2 + 465^2 .

It is a cyclic number.

It is not a de Polignac number, because 2731621 - 2⁷ = 2731493 is a prime.

2731621 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2731592 and 2731601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2731681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1365810 + 1365811.

It is an arithmetic number, because the mean of its divisors is an integer number (1365811).

2^2731621 is an apocalyptic number.

It is an amenable number.

2731621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2731621 is an equidigital number, since it uses as much as digits as its factorization.

2731621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 22.

The square root of 2731621 is about 1652.7616283058. The cubic root of 2731621 is about 139.7891554097.

Adding to 2731621 its reverse (1261372), we get a palindrome (3992993).

The spelling of 2731621 in words is "two million, seven hundred thirty-one thousand, six hundred twenty-one".