2601551581 has 2 divisors, whose sum is σ = 2601551582. Its totient is φ = 2601551580.

The previous prime is 2601551521. The next prime is 2601551609. The reversal of 2601551581 is 1851551062.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2057076025 + 544475556 = 45355^2 + 23334^2 .

It is a cyclic number.

It is not a de Polignac number, because 2601551581 - 2¹⁹ = 2601027293 is a prime.

It is a super-2 number, since 2×2601551581² = 13536141257207199122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2601551521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1300775790 + 1300775791.

It is an arithmetic number, because the mean of its divisors is an integer number (1300775791).

Almost surely, 2^2601551581 is an apocalyptic number.

It is an amenable number.

2601551581 is a deficient number, since it is larger than the sum of its proper divisors (1).

2601551581 is an equidigital number, since it uses as much as digits as its factorization.

2601551581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12000, while the sum is 34.

The square root of 2601551581 is about 51005.4073701995. The cubic root of 2601551581 is about 1375.3423422620.

The spelling of 2601551581 in words is "two billion, six hundred one million, five hundred fifty-one thousand, five hundred eighty-one".