77221806 has 16 divisors (see below), whose sum is σ = 159426048. Its totient is φ = 24910200.

The previous prime is 77221763. The next prime is 77221811. The reversal of 77221806 is 60812277.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207400 + ... + 207771.

It is an arithmetic number, because the mean of its divisors is an integer number (9964128).

Almost surely, 2^77221806 is an apocalyptic number.

77221806 is an abundant number, since it is smaller than the sum of its proper divisors (82204242).

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

77221806 is a wasteful number, since it uses less digits than its factorization.

77221806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415207.

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 77221806 is about 8787.5938686309. The cubic root of 77221806 is about 425.8401944183.

It can be divided in two parts, 772 and 21806, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 77221806 in words is "seventy-seven million, two hundred twenty-one thousand, eight hundred six".