78221012 has 12 divisors (see below), whose sum is σ = 144939060. Its totient is φ = 36809856.

The previous prime is 78220991. The next prime is 78221047. The reversal of 78221012 is 21012287.

It can be written as a sum of positive squares in 2 ways, for example, as 25745476 + 52475536 = 5074^2 + 7244^2 .

It is a super-2 number, since 2×78221012² = 12237053436608288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 575087 + ... + 575222.

It is an arithmetic number, because the mean of its divisors is an integer number (12078255).

Almost surely, 2^78221012 is an apocalyptic number.

It is an amenable number.

78221012 is a deficient number, since it is larger than the sum of its proper divisors (66718048).

78221012 is a wasteful number, since it uses less digits than its factorization.

78221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150330 (or 1150328 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 78221012 is about 8844.2643560672. The cubic root of 78221012 is about 427.6690384032.

Adding to 78221012 its reverse (21012287), we get a palindrome (99233299).

The spelling of 78221012 in words is "seventy-eight million, two hundred twenty-one thousand, twelve".