21920027 has 4 divisors (see below), whose sum is σ = 22675920. Its totient is φ = 21164136.

The previous prime is 21920023. The next prime is 21920029. The reversal of 21920027 is 72002912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21920027 - 2² = 21920023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21919984 and 21920011.

It is not an unprimeable number, because it can be changed into a prime (21920023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 377903 + ... + 377960.

It is an arithmetic number, because the mean of its divisors is an integer number (5668980).

Almost surely, 2^21920027 is an apocalyptic number.

21920027 is a deficient number, since it is larger than the sum of its proper divisors (755893).

21920027 is an equidigital number, since it uses as much as digits as its factorization.

21920027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755892.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 21920027 is about 4681.8828477441. The cubic root of 21920027 is about 279.8639943222.

Adding to 21920027 its reverse (72002912), we get a palindrome (93922939).

The spelling of 21920027 in words is "twenty-one million, nine hundred twenty thousand, twenty-seven".