772128868 has 18 divisors (see below), whose sum is σ = 1571834166. Its totient is φ = 330912288.

The previous prime is 772128853. The next prime is 772128869. The reversal of 772128868 is 868821277.

It can be written as a sum of positive squares in only one way, i.e., 493639524 + 278489344 = 22218^2 + 16688^2 .

It is a super-2 number, since 2×772128868² = 1192365977597922848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (772128869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1969521 + ... + 1969912.

Almost surely, 2^772128868 is an apocalyptic number.

It is an amenable number.

772128868 is an abundant number, since it is smaller than the sum of its proper divisors (799705298).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

772128868 is a wasteful number, since it uses less digits than its factorization.

772128868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3939451 (or 3939442 counting only the distinct ones).

The product of its digits is 602112, while the sum is 49.

The square root of 772128868 is about 27787.2069125344. The cubic root of 772128868 is about 917.4095639541.

The spelling of 772128868 in words is "seven hundred seventy-two million, one hundred twenty-eight thousand, eight hundred sixty-eight".