7501981 has 8 divisors (see below), whose sum is σ = 8217720. Its totient is φ = 6816768.

The previous prime is 7501961. The next prime is 7501987. The reversal of 7501981 is 1891057.

It can be written as a sum of positive squares in 4 ways, for example, as 3481956 + 4020025 = 1866^2 + 2005^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7501981 - 2²¹ = 5404829 is a prime.

It is a super-2 number, since 2×7501981² = 112559437848722, which contains 22 as substring.

It is a Duffinian number.

7501981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7501987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7116 + ... + 8101.

It is an arithmetic number, because the mean of its divisors is an integer number (1027215).

Almost surely, 2^7501981 is an apocalyptic number.

It is an amenable number.

7501981 is a deficient number, since it is larger than the sum of its proper divisors (715739).

7501981 is a wasteful number, since it uses less digits than its factorization.

7501981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15263.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 7501981 is about 2738.9744431082. The cubic root of 7501981 is about 195.7606146586.

The spelling of 7501981 in words is "seven million, five hundred one thousand, nine hundred eighty-one".