772551978 has 64 divisors (see below), whose sum is σ = 1789350912. Its totient is φ = 219764480.

The previous prime is 772551973. The next prime is 772551979. The reversal of 772551978 is 879155277.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 772551978.

It is not an unprimeable number, because it can be changed into a prime (772551973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 631075 + ... + 632297.

It is an arithmetic number, because the mean of its divisors is an integer number (27958608).

Almost surely, 2^772551978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 772551978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894675456).

772551978 is an abundant number, since it is smaller than the sum of its proper divisors (1016798934).

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

772551978 is a wasteful number, since it uses less digits than its factorization.

772551978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1819.

The product of its digits is 1234800, while the sum is 51.

The square root of 772551978 is about 27794.8192654674. The cubic root of 772551978 is about 917.5771069192.

The spelling of 772551978 in words is "seven hundred seventy-two million, five hundred fifty-one thousand, nine hundred seventy-eight".