21361630 has 8 divisors (see below), whose sum is σ = 38450952. Its totient is φ = 8544648.

The previous prime is 21361619. The next prime is 21361709. The reversal of 21361630 is 3616312.

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

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, 1068072 + ... + 1068091.

It is an arithmetic number, because the mean of its divisors is an integer number (4806369).

Almost surely, 2^21361630 is an apocalyptic number.

21361630 is a deficient number, since it is larger than the sum of its proper divisors (17089322).

21361630 is a wasteful number, since it uses less digits than its factorization.

21361630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2136170.

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

The square root of 21361630 is about 4621.8643424488. The cubic root of 21361630 is about 277.4670793942.

Adding to 21361630 its reverse (3616312), we get a palindrome (24977942).

The spelling of 21361630 in words is "twenty-one million, three hundred sixty-one thousand, six hundred thirty".