7677721 has 4 divisors (see below), whose sum is σ = 7942500. Its totient is φ = 7412944.

The previous prime is 7677713. The next prime is 7677751. The reversal of 7677721 is 1277767.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1277767 = 61 ⋅20947.

It can be written as a sum of positive squares in 2 ways, for example, as 4562496 + 3115225 = 2136^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 7677721 - 2³ = 7677713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7677751) 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, 132346 + ... + 132403.

It is an arithmetic number, because the mean of its divisors is an integer number (1985625).

Almost surely, 2^7677721 is an apocalyptic number.

It is an amenable number.

7677721 is a deficient number, since it is larger than the sum of its proper divisors (264779).

7677721 is a wasteful number, since it uses less digits than its factorization.

7677721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264778.

The product of its digits is 28812, while the sum is 37.

The square root of 7677721 is about 2770.8700799568. The cubic root of 7677721 is about 197.2774484000.

The spelling of 7677721 in words is "seven million, six hundred seventy-seven thousand, seven hundred twenty-one".