21920577 has 8 divisors (see below), whose sum is σ = 33402816. Its totient is φ = 12526032.

The previous prime is 21920573. The next prime is 21920621. The reversal of 21920577 is 77502912.

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

It is not a de Polignac number, because 21920577 - 2² = 21920573 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21920573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521898 + ... + 521939.

It is an arithmetic number, because the mean of its divisors is an integer number (4175352).

Almost surely, 2^21920577 is an apocalyptic number.

It is an amenable number.

21920577 is a deficient number, since it is larger than the sum of its proper divisors (11482239).

21920577 is a wasteful number, since it uses less digits than its factorization.

21920577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1043847.

The product of its (nonzero) digits is 8820, while the sum is 33.

The square root of 21920577 is about 4681.9415844284. The cubic root of 21920577 is about 279.8663350114.

The spelling of 21920577 in words is "twenty-one million, nine hundred twenty thousand, five hundred seventy-seven".