21613630 has 16 divisors (see below), whose sum is σ = 41193360. Its totient is φ = 8136832.

The previous prime is 21613619. The next prime is 21613639. The reversal of 21613630 is 3631612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613639) 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 7 ways as a sum of consecutive naturals, for example, 63400 + ... + 63739.

It is an arithmetic number, because the mean of its divisors is an integer number (2574585).

Almost surely, 2^21613630 is an apocalyptic number.

21613630 is a deficient number, since it is larger than the sum of its proper divisors (19579730).

21613630 is a wasteful number, since it uses less digits than its factorization.

21613630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127163.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21613630 is about 4649.0461387257. The cubic root of 21613630 is about 278.5538962699.

The spelling of 21613630 in words is "twenty-one million, six hundred thirteen thousand, six hundred thirty".