5621201581 has 2 divisors, whose sum is σ = 5621201582. Its totient is φ = 5621201580.

The previous prime is 5621201527. The next prime is 5621201609. The reversal of 5621201581 is 1851021265.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4769145481 + 852056100 = 69059^2 + 29190^2 .

It is a cyclic number.

It is not a de Polignac number, because 5621201581 - 2²¹ = 5619104429 is a prime.

It is a super-2 number, since 2×5621201581² = 63195814428473799122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5621201381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2810600790 + 2810600791.

It is an arithmetic number, because the mean of its divisors is an integer number (2810600791).

Almost surely, 2^5621201581 is an apocalyptic number.

It is an amenable number.

5621201581 is a deficient number, since it is larger than the sum of its proper divisors (1).

5621201581 is an equidigital number, since it uses as much as digits as its factorization.

5621201581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4800, while the sum is 31.

The square root of 5621201581 is about 74974.6729302636. The cubic root of 5621201581 is about 1778.0462488861.

It can be divided in two parts, 562120 and 1581, that multiplied together give a triangular number (888711720 = T₄₂₁₅₉).

The spelling of 5621201581 in words is "five billion, six hundred twenty-one million, two hundred one thousand, five hundred eighty-one".