21327690 has 128 divisors (see below), whose sum is σ = 59719680. Its totient is φ = 4838400.

The previous prime is 21327689. The next prime is 21327701. The reversal of 21327690 is 9672312.

It is a super-2 number, since 2×21327690² = 909740721472200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 300355 + ... + 300425.

It is an arithmetic number, because the mean of its divisors is an integer number (466560).

Almost surely, 2^21327690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21327690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29859840).

21327690 is an abundant number, since it is smaller than the sum of its proper divisors (38391990).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21327690 is a wasteful number, since it uses less digits than its factorization.

21327690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 21327690 is about 4618.1912043570. The cubic root of 21327690 is about 277.3200521536.

The spelling of 21327690 in words is "twenty-one million, three hundred twenty-seven thousand, six hundred ninety".