21320827 has 4 divisors (see below), whose sum is σ = 23259096. Its totient is φ = 19382560.

The previous prime is 21320821. The next prime is 21320833. The reversal of 21320827 is 72802312.

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

It is an interprime number because it is at equal distance from previous prime (21320821) and next prime (21320833).

It is a cyclic number.

It is not a de Polignac number, because 21320827 - 2²³ = 12932219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320821) 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 3 ways as a sum of consecutive naturals, for example, 969118 + ... + 969139.

It is an arithmetic number, because the mean of its divisors is an integer number (5814774).

Almost surely, 2^21320827 is an apocalyptic number.

21320827 is a deficient number, since it is larger than the sum of its proper divisors (1938269).

21320827 is a wasteful number, since it uses less digits than its factorization.

21320827 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1938268.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21320827 is about 4617.4481047436. The cubic root of 21320827 is about 277.2903028511.

The spelling of 21320827 in words is "twenty-one million, three hundred twenty thousand, eight hundred twenty-seven".