2157641 has 2 divisors, whose sum is σ = 2157642. Its totient is φ = 2157640.

The previous prime is 2157587. The next prime is 2157667. The reversal of 2157641 is 1467512.

It is an a-pointer prime, because the next prime (2157667) can be obtained adding 2157641 to its sum of digits (26).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2042041 + 115600 = 1429^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157641 - 2¹⁰ = 2156617 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2157641.

It is not a weakly prime, because it can be changed into another prime (2157671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078820 + 1078821.

It is an arithmetic number, because the mean of its divisors is an integer number (1078821).

2^2157641 is an apocalyptic number.

It is an amenable number.

2157641 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157641 is an equidigital number, since it uses as much as digits as its factorization.

2157641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 26.

The square root of 2157641 is about 1468.8910783309. The cubic root of 2157641 is about 129.2190058210.

The spelling of 2157641 in words is "two million, one hundred fifty-seven thousand, six hundred forty-one".