21072927 has 4 divisors (see below), whose sum is σ = 28097240. Its totient is φ = 14048616.

The previous prime is 21072923. The next prime is 21072973. The reversal of 21072927 is 72927012.

It is a happy number.

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

It is not a de Polignac number, because 21072927 - 2² = 21072923 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21072894 and 21072903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21072923) 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 3 ways as a sum of consecutive naturals, for example, 3512152 + ... + 3512157.

It is an arithmetic number, because the mean of its divisors is an integer number (7024310).

Almost surely, 2^21072927 is an apocalyptic number.

21072927 is a deficient number, since it is larger than the sum of its proper divisors (7024313).

21072927 is an equidigital number, since it uses as much as digits as its factorization.

21072927 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7024312.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 21072927 is about 4590.5257868789. The cubic root of 21072927 is about 276.2114138417.

Adding to 21072927 its reverse (72927012), we get a palindrome (93999939).

It can be divided in two parts, 210 and 72927, that added together give a palindrome (73137).

The spelling of 21072927 in words is "twenty-one million, seventy-two thousand, nine hundred twenty-seven".