7723981 has 4 divisors (see below), whose sum is σ = 7730172. Its totient is φ = 7717792.

The previous prime is 7723979. The next prime is 7723997. The reversal of 7723981 is 1893277.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 4447881 + 3276100 = 2109^2 + 1810^2 .

It is a cyclic number.

It is not a de Polignac number, because 7723981 - 2¹ = 7723979 is a prime.

It is a super-2 number, since 2×7723981² = 119319764976722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7723981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7723081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496 + ... + 3961.

It is an arithmetic number, because the mean of its divisors is an integer number (1932543).

Almost surely, 2^7723981 is an apocalyptic number.

It is an amenable number.

7723981 is a deficient number, since it is larger than the sum of its proper divisors (6191).

7723981 is a wasteful number, since it uses less digits than its factorization.

7723981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6190.

The product of its digits is 21168, while the sum is 37.

The square root of 7723981 is about 2779.2051021830. The cubic root of 7723981 is about 197.6728689953.

It can be divided in two parts, 772 and 3981, that added together give a triangular number (4753 = T₉₇).

The spelling of 7723981 in words is "seven million, seven hundred twenty-three thousand, nine hundred eighty-one".