7721965 has 8 divisors (see below), whose sum is σ = 9282168. Its totient is φ = 6167040.

The previous prime is 7721963. The next prime is 7721969. The reversal of 7721965 is 5691277.

It can be written as a sum of positive squares in 4 ways, for example, as 203401 + 7518564 = 451^2 + 2742^2 .

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

It is not a de Polignac number, because 7721965 - 2¹ = 7721963 is a prime.

It is a super-2 number, since 2×7721965² = 119257486922450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7721963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3529 + ... + 5281.

It is an arithmetic number, because the mean of its divisors is an integer number (1160271).

Almost surely, 2^7721965 is an apocalyptic number.

It is an amenable number.

7721965 is a deficient number, since it is larger than the sum of its proper divisors (1560203).

7721965 is a wasteful number, since it uses less digits than its factorization.

7721965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2639.

The product of its digits is 26460, while the sum is 37.

The square root of 7721965 is about 2778.8423848790. The cubic root of 7721965 is about 197.6556696099.

It can be divided in two parts, 77219 and 65, that added together give a square (77284 = 278²).

The spelling of 7721965 in words is "seven million, seven hundred twenty-one thousand, nine hundred sixty-five".