2153561 has 2 divisors, whose sum is σ = 2153562. Its totient is φ = 2153560.

The previous prime is 2153551. The next prime is 2153563. The reversal of 2153561 is 1653512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2088025 + 65536 = 1445^2 + 256^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2153561 is a prime.

Together with 2153563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2153563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1076780 + 1076781.

It is an arithmetic number, because the mean of its divisors is an integer number (1076781).

2^2153561 is an apocalyptic number.

It is an amenable number.

2153561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2153561 is an equidigital number, since it uses as much as digits as its factorization.

2153561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 900, while the sum is 23.

The square root of 2153561 is about 1467.5016183977. The cubic root of 2153561 is about 129.1375053605.

The spelling of 2153561 in words is "two million, one hundred fifty-three thousand, five hundred sixty-one".