7755721 has 2 divisors, whose sum is σ = 7755722. Its totient is φ = 7755720.

The previous prime is 7755697. The next prime is 7755767. The reversal of 7755721 is 1275577.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4644025 + 3111696 = 2155^2 + 1764^2 .

It is a cyclic number.

It is not a de Polignac number, because 7755721 - 2¹¹ = 7753673 is a prime.

It is not a weakly prime, because it can be changed into another prime (7755421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3877860 + 3877861.

It is an arithmetic number, because the mean of its divisors is an integer number (3877861).

Almost surely, 2^7755721 is an apocalyptic number.

It is an amenable number.

7755721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7755721 is an equidigital number, since it uses as much as digits as its factorization.

7755721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17150, while the sum is 34.

The square root of 7755721 is about 2784.9095137903. The cubic root of 7755721 is about 197.9432633411.

The spelling of 7755721 in words is "seven million, seven hundred fifty-five thousand, seven hundred twenty-one".