21777061 has 8 divisors (see below), whose sum is σ = 22419200. Its totient is φ = 21144240.

The previous prime is 21777043. The next prime is 21777073. The reversal of 21777061 is 16077712.

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

It is a cyclic number.

It is not a de Polignac number, because 21777061 - 2⁹ = 21776549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21777031) 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 7 ways as a sum of consecutive naturals, for example, 2560 + ... + 7078.

It is an arithmetic number, because the mean of its divisors is an integer number (2802400).

Almost surely, 2^21777061 is an apocalyptic number.

It is an amenable number.

21777061 is a deficient number, since it is larger than the sum of its proper divisors (642139).

21777061 is an equidigital number, since it uses as much as digits as its factorization.

21777061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4659.

The product of its (nonzero) digits is 4116, while the sum is 31.

The square root of 21777061 is about 4666.5898684157. The cubic root of 21777061 is about 279.2542271513.

The spelling of 21777061 in words is "twenty-one million, seven hundred seventy-seven thousand, sixty-one".