780772221 has 6 divisors (see below), whose sum is σ = 1127782110. Its totient is φ = 520514808.

The previous prime is 780772219. The next prime is 780772229. The reversal of 780772221 is 122277087.

It can be written as a sum of positive squares in only one way, i.e., 776235321 + 4536900 = 27861^2 + 2130^2 .

It is not a de Polignac number, because 780772221 - 2¹ = 780772219 is a prime.

It is a super-2 number, since 2×780772221² = 1219210522170545682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780772229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43376226 + ... + 43376243.

It is an arithmetic number, because the mean of its divisors is an integer number (187963685).

Almost surely, 2^780772221 is an apocalyptic number.

It is an amenable number.

780772221 is a deficient number, since it is larger than the sum of its proper divisors (347009889).

780772221 is a wasteful number, since it uses less digits than its factorization.

780772221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86752475 (or 86752472 counting only the distinct ones).

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

The square root of 780772221 is about 27942.3016410603. The cubic root of 780772221 is about 920.8200867328.

The spelling of 780772221 in words is "seven hundred eighty million, seven hundred seventy-two thousand, two hundred twenty-one".