7511981 has 2 divisors, whose sum is σ = 7511982. Its totient is φ = 7511980.

The previous prime is 7511969. The next prime is 7511989. The reversal of 7511981 is 1891157.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6375625 + 1136356 = 2525^2 + 1066^2 .

It is a cyclic number.

It is not a de Polignac number, because 7511981 - 2¹⁴ = 7495597 is a prime.

It is a super-2 number, since 2×7511981² = 112859717088722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7511989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3755990 + 3755991.

It is an arithmetic number, because the mean of its divisors is an integer number (3755991).

Almost surely, 2^7511981 is an apocalyptic number.

It is an amenable number.

7511981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7511981 is an equidigital number, since it uses as much as digits as its factorization.

7511981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 32.

The square root of 7511981 is about 2740.7993359602. The cubic root of 7511981 is about 195.8475577817.

The spelling of 7511981 in words is "seven million, five hundred eleven thousand, nine hundred eighty-one".