772221 has 4 divisors (see below), whose sum is σ = 1029632. Its totient is φ = 514812.

The previous prime is 772207. The next prime is 772229. The reversal of 772221 is 122277.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122277 = 3 ⋅40759.

It is not a de Polignac number, because 772221 - 2¹⁸ = 510077 is a prime.

It is a D-number.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (772229) 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, 128701 + ... + 128706.

It is an arithmetic number, because the mean of its divisors is an integer number (257408).

2⁷⁷²²²¹ is an apocalyptic number.

It is an amenable number.

772221 is a deficient number, since it is larger than the sum of its proper divisors (257411).

772221 is a wasteful number, since it uses less digits than its factorization.

772221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257410.

The product of its digits is 392, while the sum is 21.

The square root of 772221 is about 878.7610596744. The cubic root of 772221 is about 91.7446051566.

Adding to 772221 its reverse (122277), we get a palindrome (894498).

The spelling of 772221 in words is "seven hundred seventy-two thousand, two hundred twenty-one", and thus it is an iban number.