72778212 has 36 divisors (see below), whose sum is σ = 198119740. Its totient is φ = 22393152.

The previous prime is 72778171. The next prime is 72778213. The reversal of 72778212 is 21287727.

It can be written as a sum of positive squares in 2 ways, for example, as 27941796 + 44836416 = 5286^2 + 6696^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (72778213) 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 11 ways as a sum of consecutive naturals, for example, 77287 + ... + 78222.

Almost surely, 2^72778212 is an apocalyptic number.

It is an amenable number.

72778212 is an abundant number, since it is smaller than the sum of its proper divisors (125341528).

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

72778212 is a wasteful number, since it uses less digits than its factorization.

72778212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155532 (or 155527 counting only the distinct ones).

The product of its digits is 21952, while the sum is 36.

The square root of 72778212 is about 8531.0147110411. The cubic root of 72778212 is about 417.5102358039.

The spelling of 72778212 in words is "seventy-two million, seven hundred seventy-eight thousand, two hundred twelve".