21779061 has 8 divisors (see below), whose sum is σ = 29167584. Its totient is φ = 14454960.

The previous prime is 21779033. The next prime is 21779063. The reversal of 21779061 is 16097712.

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

It is not a de Polignac number, because 21779061 - 2¹¹ = 21777013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21779063) 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, 15310 + ... + 16671.

It is an arithmetic number, because the mean of its divisors is an integer number (3645948).

Almost surely, 2^21779061 is an apocalyptic number.

It is an amenable number.

21779061 is a deficient number, since it is larger than the sum of its proper divisors (7388523).

21779061 is a wasteful number, since it uses less digits than its factorization.

21779061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32211.

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 21779061 is about 4666.8041527366. The cubic root of 21779061 is about 279.2627757698.

The spelling of 21779061 in words is "twenty-one million, seven hundred seventy-nine thousand, sixty-one".