2154243521 has 2 divisors, whose sum is σ = 2154243522. Its totient is φ = 2154243520.

The previous prime is 2154243499. The next prime is 2154243527. The reversal of 2154243521 is 1253424512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1821582400 + 332661121 = 42680^2 + 18239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2154243521 is a prime.

It is not a weakly prime, because it can be changed into another prime (2154243527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077121760 + 1077121761.

It is an arithmetic number, because the mean of its divisors is an integer number (1077121761).

Almost surely, 2^2154243521 is an apocalyptic number.

It is an amenable number.

2154243521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2154243521 is an equidigital number, since it uses as much as digits as its factorization.

2154243521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9600, while the sum is 29.

The square root of 2154243521 is about 46413.8289844740. The cubic root of 2154243521 is about 1291.5114629437.

The spelling of 2154243521 in words is "two billion, one hundred fifty-four million, two hundred forty-three thousand, five hundred twenty-one".