7551019981 has 2 divisors, whose sum is σ = 7551019982. Its totient is φ = 7551019980.

The previous prime is 7551019967. The next prime is 7551020023. The reversal of 7551019981 is 1899101557.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5659552900 + 1891467081 = 75230^2 + 43491^2 .

It is an emirp because it is prime and its reverse (1899101557) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7551019981 - 2¹³ = 7551011789 is a prime.

It is a super-2 number, since 2×7551019981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7551019781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3775509990 + 3775509991.

It is an arithmetic number, because the mean of its divisors is an integer number (3775509991).

Almost surely, 2^7551019981 is an apocalyptic number.

It is an amenable number.

7551019981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7551019981 is an equidigital number, since it uses as much as digits as its factorization.

7551019981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 113400, while the sum is 46.

The square root of 7551019981 is about 86896.6051178065. The cubic root of 7551019981 is about 1961.8623819898.

The spelling of 7551019981 in words is "seven billion, five hundred fifty-one million, nineteen thousand, nine hundred eighty-one".