21920630 has 8 divisors (see below), whose sum is σ = 39457152. Its totient is φ = 8768248.

The previous prime is 21920621. The next prime is 21920651. The reversal of 21920630 is 3602912.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21920596 and 21920605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096022 + ... + 1096041.

It is an arithmetic number, because the mean of its divisors is an integer number (4932144).

Almost surely, 2^21920630 is an apocalyptic number.

21920630 is a deficient number, since it is larger than the sum of its proper divisors (17536522).

21920630 is a wasteful number, since it uses less digits than its factorization.

21920630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2192070.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21920630 is about 4681.9472444700. The cubic root of 21920630 is about 279.8665605666.

The spelling of 21920630 in words is "twenty-one million, nine hundred twenty thousand, six hundred thirty".