2154520035581 has 2 divisors, whose sum is σ = 2154520035582. Its totient is φ = 2154520035580.

The previous prime is 2154520035539. The next prime is 2154520035653. The reversal of 2154520035581 is 1855300254512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1502318427481 + 652201608100 = 1225691^2 + 807590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2154520035581 is a prime.

It is a super-2 number, since 2×2154520035581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2154520035181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077260017790 + 1077260017791.

It is an arithmetic number, because the mean of its divisors is an integer number (1077260017791).

Almost surely, 2^{2154520035581} is an apocalyptic number.

It is an amenable number.

2154520035581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2154520035581 is an equidigital number, since it uses as much as digits as its factorization.

2154520035581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240000, while the sum is 41.

The spelling of 2154520035581 in words is "two trillion, one hundred fifty-four billion, five hundred twenty million, thirty-five thousand, five hundred eighty-one".