220766721 has 8 divisors (see below), whose sum is σ = 336406464. Its totient is φ = 126152400.

The previous prime is 220766713. The next prime is 220766723. The reversal of 220766721 is 127667022.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 220766721 - 2³ = 220766713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (220766723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5256330 + ... + 5256371.

It is an arithmetic number, because the mean of its divisors is an integer number (42050808).

Almost surely, 2^220766721 is an apocalyptic number.

220766721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

220766721 is a deficient number, since it is larger than the sum of its proper divisors (115639743).

220766721 is a wasteful number, since it uses less digits than its factorization.

220766721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10512711.

The product of its (nonzero) digits is 14112, while the sum is 33.

The square root of 220766721 is about 14858.2206539007. The cubic root of 220766721 is about 604.3815559483.

It can be divided in two parts, 220 and 766721, that added together give a triangular number (766941 = T₁₂₃₈).

The spelling of 220766721 in words is "two hundred twenty million, seven hundred sixty-six thousand, seven hundred twenty-one".