7721387 has 8 divisors (see below), whose sum is σ = 8012160. Its totient is φ = 7433280.

The previous prime is 7721377. The next prime is 7721393. The reversal of 7721387 is 7831277.

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 7721387 - 2¹⁴ = 7705003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7721347) 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, 6689 + ... + 7757.

It is an arithmetic number, because the mean of its divisors is an integer number (1001520).

Almost surely, 2^7721387 is an apocalyptic number.

7721387 is a deficient number, since it is larger than the sum of its proper divisors (290773).

7721387 is a wasteful number, since it uses less digits than its factorization.

7721387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333.

The product of its digits is 16464, while the sum is 35.

The square root of 7721387 is about 2778.7383827917. The cubic root of 7721387 is about 197.6507378847.

The spelling of 7721387 in words is "seven million, seven hundred twenty-one thousand, three hundred eighty-seven".