21730146 has 8 divisors (see below), whose sum is σ = 43460304. Its totient is φ = 7243380.

The previous prime is 21730139. The next prime is 21730169. The reversal of 21730146 is 64103712.

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

21730146 is an admirable 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, 1810840 + ... + 1810851.

It is an arithmetic number, because the mean of its divisors is an integer number (5432538).

Almost surely, 2^21730146 is an apocalyptic number.

21730146 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21730146 is a wasteful number, since it uses less digits than its factorization.

21730146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3621696.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21730146 is about 4661.5604683410. The cubic root of 21730146 is about 279.0535476158.

Adding to 21730146 its reverse (64103712), we get a palindrome (85833858).

The spelling of 21730146 in words is "twenty-one million, seven hundred thirty thousand, one hundred forty-six".