21627381 has 8 divisors (see below), whose sum is σ = 29242944. Its totient is φ = 14215040.

The previous prime is 21627373. The next prime is 21627401. The reversal of 21627381 is 18372612.

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

It is a cyclic number.

It is not a de Polignac number, because 21627381 - 2³ = 21627373 is a prime.

It is a super-2 number, since 2×21627381² = 935487217838322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21627311) 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 7 ways as a sum of consecutive naturals, for example, 50556 + ... + 50981.

It is an arithmetic number, because the mean of its divisors is an integer number (3655368).

Almost surely, 2^21627381 is an apocalyptic number.

It is an amenable number.

21627381 is a deficient number, since it is larger than the sum of its proper divisors (7615563).

21627381 is a wasteful number, since it uses less digits than its factorization.

21627381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101611.

The product of its digits is 4032, while the sum is 30.

The square root of 21627381 is about 4650.5248090941. The cubic root of 21627381 is about 278.6129574979.

Adding to 21627381 its reverse (18372612), we get a palindrome (39999993).

The spelling of 21627381 in words is "twenty-one million, six hundred twenty-seven thousand, three hundred eighty-one".